What’s New
Recent calculator, reference-data, reporting, support, and website improvements.
September 6, 2026
Electrical Box Fill Calculator
Added a scoped 2023 NEC 314.16 workbench for 18 AWG through 6 AWG conductors in one undivided outlet, device, or junction-box space. The five-step no-scroll workflow requires explicit confirmation of usable box volume, counts ordinary conductors and 300.14-length qualifying loops or coils, applies the four-entering-EGC threshold and quarter allowances beyond four, and separately includes ordinary internal clamps, luminaire studs, hickeys, device yokes, and the 2023 terminal-block-assembly allowance. Results show every rule, governing conductor size, allowance count, required volume, remaining volume, and an unrounded pass/fail decision. Versioned fragment share links require the recipient to reconfirm box volume; branded PDF/CSV output, authoritative references, calculation boundary tests, FAQ data, metadata, sitemap coverage, and calculator navigation are included.
August 16, 2026
Fiber Optic Maximum Distance Calculator
Added the fourth released fiber calculator for loss-limited reach planning. The workbench derives equipment power budget from minimum transmitter output and receiver sensitivity, subtracts connections, splices, other passive loss, and engineering reserve, then divides the remaining fiber-loss allowance by the selected attenuation. An optional equipment, application, or project reach limit governs when it is shorter. Results clearly warn that attenuation budget alone does not verify modal bandwidth, chromatic dispersion, optical path penalties, or published protocol reach. Equipment, Fixed loss, and Fiber & reserve use consistent field cards with a readable full-width profile selector, compact live-result treatment, and single-column phone layout. Physical-unit conversion preserves an entered reach limit, exact-zero budgets produce an accurate no-distance explanation, and very large mathematically supported results remain renderable. Link Budget handoffs work in both directions within its supported range and explain when an entered reach limit is needed before handoff. Share restoration, CSV, a branded one-page engineering PDF, focused boundary tests, unique metadata, and structured FAQ data are included.
August 16, 2026
Fiber Optic Splitter Loss Calculator
Added the third released fiber calculator for balanced 1×N splitter stages and cascaded paths. It separates theoretical division loss, documented excess loss, and complete published insertion loss so ideal loss is never counted twice. Optional input power produces an expected equivalent-output level, while stage-by-stage Results, Link Budget handoff, share restoration, CSV, and a branded engineering PDF preserve the complete design basis. The Fiber hub restores the compact multi-column calculator-card layout at 100% desktop zoom while continuing to hide every unfinished calculator.
August 15, 2026
Complete conduit-plan jam-risk handoff
Conduit Fill now transfers an entire completed multi-conduit plan to Conduit Jam Ratio instead of placing the full cable schedule into one conduit. Jam Ratio automatically evaluates every physical run, including unequal cable allocations and mixed conduit sizes, then reports one governing plan result with maximum run fill and the highest published jam-risk classification. Run allocations remain available as supporting verification rather than a quantity the user must choose. Plan-aware share links, CSV and print records, and a complete-plan handoff back to Conduit Fill are included; the existing single-conduit workflow is unchanged.
August 15, 2026
dBm and mW optical power converter
Added the second dedicated fiber calculator as a compact five-step dBm-to-mW and mW-to-dBm workflow. It preserves the exact physical power when direction changes, keeps full precision internally, validates the undefined zero and negative milliwatt boundary, and shows equivalent dBm, milliwatts, watts, and microwatts. Clear guidance distinguishes absolute dBm referenced to 1 mW from a dB ratio. Versioned share links, complete CSV output, a branded engineering PDF, unique search metadata, structured FAQ data, and focused inverse-conversion regression tests are included. The Fiber hub now publishes both completed calculators while tools 3–11 remain hidden until release.
August 15, 2026
Full-page calculator and site layouts
Standardized every calculator as a true one-viewport workbench at 100% browser zoom by including shell padding inside the viewport height, removing remaining desktop margins and width caps, and preserving internal scrolling for long controls and results. All Calculators now expands fluidly as zoom changes. Every destination in Help & site links now uses the same compact calculator-style logo, calculator menu, site-links menu, and sticky full-width header inside a one-viewport page shell. Mobile menus remain inside the screen, all five calculator tabs remain visible, and no calculation logic, defaults, formulas, results, exports, or handoffs changed.
August 15, 2026
Fiber Optic Link Budget Calculator
Added the first dedicated fiber calculator as a compact five-step workbench for defining the fiber run, counting connections, splices, and passive-device loss, entering optional active-equipment specifications, reviewing the governing optical margin, and exporting the plan. The equipment step now maps complete manufacturer ranges: minimum TX governs sensitivity and link margin, while maximum TX separately governs receiver overload. A compact How to use guide, negative-dBm examples, aligned range fields, automatic step scroll reset, and actionable validation make the workflow easier to follow without inventing transceiver defaults. Loss-only projects remain usable in REVIEW. A final calculation audit now rejects zero operating margin and blank required loss/reserve fields while allowing a positive margin that exactly satisfies the selected reserve. Versioned share links, complete CSV output, and a branded one-page engineering report provide the design basis, governing calculations, receiver checks, result interpretation, formulas, and verification notes. The Fiber hub now publishes only completed and verified calculators while retaining unreleased tool definitions for staged development. Focused calculation regressions, unique metadata, FAQ and WebApplication structured data, and direct Fiber hub navigation are included.
August 14, 2026
Fiber optic calculator foundation
Added a dedicated, crawlable Fiber Optic Calculators hub led by Optical Link Budget. The compact viewport workspace uses the same shared header and responsive page width as the calculators, while keyboard-accessible panels keep released calculators, references, and FAQ available without a long page scroll. Only completed and verified fiber calculators are shown publicly; planned tools remain staged for one-at-a-time release. Existing conduit and pathway calculators are intentionally excluded from the Fiber page. The hub also introduces a tested shared model for OM/OS fiber classes, common wavelengths, and clearly labeled FOA / NECA loss-budget planning profiles.
August 10, 2026
Clearer pull-box sizing and mobile workbenches
Communications and fiber pull-box planning no longer presents a silent 8 × 8 × 4 default as though conduit trade sizes calculated it. Cable modes now ask for an intentional proposed inside box, explain that the conduit sizes document openings rather than determine the enclosure, and retain the optional manufacturer bend-envelope check. Power mode continues to calculate NEC 314.28 dimensions from the entered conduit layout. Cable Tray Fill Results now scroll internally on phone-size screens in both Summary and Tray view. All standardized five-step workbenches expose Steps 1–5 simultaneously on phones instead of hiding Results and Export beyond an unmarked horizontal scroll. The shared 4-inch-versus-four-2-inch EMT article teaser is visible in calculator headers on larger screens and intentionally hidden on phones to preserve working space.
August 10, 2026
Power, low-voltage, and fiber pull-box planning
Redesigned the Pull Box Size Calculator so the normal workflow is simply Add conduit, choose where it enters the enclosure, and choose the trade size. Asymmetric layouts no longer require duplicate entries or row setup, and Back is a supported entry surface for conduits passing through the mounting wall. Power mode preserves the NEC 314.28 calculation while making the largest 4 AWG–2000 kcmil Back-entry conductor an optional depth-check enhancement: omitted data keeps the plan exportable as REVIEW, partial data is clearly provisional, and no hidden conductor size is assumed. Communications / low-voltage and Fiber-optic modes begin with the same easy quick-planning REVIEW; a collapsed optional group adds actual cable or bundle diameter plus manufacturer installation and installed bend radii when a conservative bend-envelope check is wanted. Diagrams, conditional CSV/PDF content, and version 4 share links preserve the selected application and optional verification inputs while retaining older power-calculation links.
August 10, 2026
Conduit calculator release-readiness pass
Completed a calculator-by-calculator review of Conduit Fill, Conduit Size, Conduit Cable Capacity, Conduit Jam Ratio, Offset and Rolling Offset, 3-Point Saddle, 4-Point Saddle, and 90° Stub-Up. The pass corrected complete project-aware share restoration, physical unit conversion, invalid and boundary recovery, governing recommendations and handoffs, result-first ordering, full CSV records, mobile tab/menu overflow, and PDF page splitting. Saddle stock checks now reach the farthest mark from START and withhold instructions for impossible negative marks; Stub-Up preserves validated bender-preset context and checks available stock against the finished dimension; Conduit Size reports the actual recommended design; Capacity safely handles oversized custom cable; and Jam Ratio keeps conduit fill as the governing quantity decision while preserving the separate diameter-risk classification. Every final PDF was rendered and visually inspected. The How to Use page now teaches the shared five-step workflow before asking visitors to choose a calculator.
August 9, 2026
Focused electrical sizing workflows
Redesigned Wire Ampacity, Equipment Grounding Conductor, Voltage Drop, and Branch Circuit Wire Size as full-page five-step workbenches. Each calculator now separates setup decisions into task-specific steps, keeps the live decision visible on desktop, provides a dedicated Results view, and moves PDF, CSV, and share controls into Step 5. A release-readiness pass added dynamic step headings, roving keyboard focus, visible invalid Results states, guarded PDF/CSV actions, project-aware share restoration, fuller calculation CSVs, and expanded boundary regression coverage. Branch Circuit keeps Load, Installation, and Protection correctly grouped in AC and DC modes; Voltage Drop safely handles invalid feeder/branch inputs and leads Results with the governing coordination decision; Equipment Grounding requires explicit protective-device confirmation on coordinated handoffs and transfers separate phase and ground rows to Conduit Size. Electrical PDF reports include compact input and calculated-decision summaries followed by the applicable formulas, comparisons, and verification notes; the coordinated Branch Circuit report fits on one page.
August 9, 2026
Focused Cable Tray Fill workflow
Redesigned Cable Tray Fill as a five-step full-page workbench for choosing a tray, entering cable groups, setting the fill method and installation allowance, reviewing capacity and the calculated tray cross-section, and exporting the plan. Results use a compact decision panel beside a large tray view on desktop and dedicated Summary/Tray view subtabs on mobile. A release-readiness pass added imperial and metric display, explicit PASS/REVISE decisions, governing area and side-by-side formulas, missing-area or missing-width reporting, an available-tray action, safe project-aware share restoration, fuller dual-unit CSV records, guarded invalid exports, and two-page reports with intact decision boxes. PDF, CSV, and share controls live in Step 5.
August 9, 2026
Focused Pull Box Size workflow
Redesigned Pull Box Size as a five-step full-page workbench for choosing units, entering paired conduit runs, checking proposed usable-inside dimensions, reviewing governing straight/angle/U-pull requirements, and exporting the report or diagram. A release-readiness pass added unit-correct proposed-box entry, consistent invalid recovery and guarded exports, an early apply-calculated-dimensions action, safe project-aware share restoration, complete governing and paired-spacing CSV records, zoom-resistant tabs, and a compact report with Results before an intact diagram page. Step 5 contains PDF, CSV, SVG, PNG, and share controls.
August 9, 2026
Guided 90° Conduit Stub-Up workflow
Redesigned the Stub-Up calculator as a five-step full-page workbench for selecting conduit, entering finished height, confirming exact bender take-up, reviewing the arrow-mark formula and field sequence, and exporting a worksheet. Beginner instructions identify the STUB END, arrow reference, hook and handle orientation, 90-degree target, springback check, and finished-height verification while preserving the calculated diagram and optional verified presets.
August 9, 2026
Streamlined 3-Point and 4-Point Saddle workflows
Redesigned both conduit saddle calculators as five-step workbenches for choosing the conduit, entering obstruction geometry, checking available field space, reviewing calculated marks and formulas, and exporting a worksheet. Separate beginner-friendly field sequences identify START, explain the physical mark order versus bending order, name the center rim/notch or arrow reference, show bend direction and conduit rotation, and preserve the calculated saddle diagrams.
August 9, 2026
Results and recommendations now come first
Reordered the detailed Results tabs in the migrated conduit calculators so the primary answer and actions such as Use recommended size or Use this conduit plan appear before large conduit and bending illustrations. The calculated SVG and proportional cross-section visuals remain available immediately below the decision content and continue to appear in reports.
August 9, 2026
Streamlined Offset and Rolling Offset workflow
Redesigned the combined conduit offset calculator as a five-step, viewport-height workbench for choosing standard or rolling mode, entering geometry, checking available field space, reviewing the calculated diagram and marking sequence, and exporting a worksheet. The field overlay now gives beginners a direct seven-step sequence from choosing the starting end through marking, bending, rotating, and verifying the finished conduit, while retaining calculated spacing, rolling-plane rotation, formulas, and tool-specific limitations. Printed instruction cards now stay intact across PDF page boundaries.
August 9, 2026
Focused Conduit Jam Ratio workflow
Redesigned Conduit Jam Ratio as a five-step, viewport-height workbench for selecting the conduit, choosing one repeated round cable, checking quantity and published jamming-risk bands, reviewing the proportional pull cross-section and detailed calculations, and exporting the report. The workflow keeps diameter-based jamming risk separate from quantity-based conduit fill, while PDF and CSV exports include project context, formula, fill limits, risk classification, and field-verification guidance.
August 8, 2026
Faster Conduit Cable Capacity workflow
Redesigned Conduit Cable Capacity as a five-step, viewport-height workbench for selecting a conduit, choosing one repeated cable, setting the fill criterion, reviewing maximum whole-cable capacity, and exporting the report. The detailed result retains the proportional bundle and same-material size comparison, while PDF and CSV exports now include project context and maximum-load formulas.
August 8, 2026
Purpose-built Conduit Fill and Conduit Size workspaces
Redesigned both calculators as fluid, viewport-height, five-step workbenches. Conduit Fill starts with a selected conduit; Conduit Size starts with the cable load and treats raceway type and maximum size as project limits before presenting a recommendation. Live sizing results identify the quantity and size of every recommended conduit group. A dedicated Export step provides PDF and CSV reports with detailed engineering results and formulas, compact unbroken conduit drawings, and planned-fill metrics. Proportional cross-sections use an illustrative loosely settled bundle and a separate fill gauge, while compact navigation preserves crawlable site links.
August 5, 2026
Automatic ground wire allowance for conduit fill
Added an electrical-only option in Conduit Fill and Conduit Size to calculate one supported wire-type equipment grounding conductor from the confirmed protective-device and phase-conductor inputs, require an exact published product diameter, and include its physical area in fill and conduit-size recommendations. Telecommunications and data projects are unchanged.
August 5, 2026
Interactive conduit-bending instructions
Added collapsible, input-responsive marking and bending sequences for standard offsets, rolling offsets, three-point saddles, and four-point saddles. The overlays identify the starting end, numbered bend order, bender reference symbol, handle and bend direction, rolling-plane rotation, calculated spacing and shrink, and model-specific verification limits while preserving the calculated field diagrams.
August 5, 2026
Proportional conduit cross-section previews
Added interactive SVG cross-sections to Conduit Fill, Conduit Size, Conduit Cable Capacity, and Conduit Jam Ratio. The previews draw conduit and cable diameters proportionally, distinguish mixed cable groups, show multi-conduit distribution, report exact or representative symbol counts, and clearly separate illustrative packing from the governing calculations.
August 2, 2026
Branch Circuit Wire Size Calculator
Added a guided common-circuit workflow that coordinates the existing ampacity, voltage-drop, and equipment-grounding engines, checks a user-confirmed protective device, produces branded PDF/CSV reports and share links, and transfers the final circuit conductors plus EGC to Conduit Size for exact product selection.
August 1, 2026
Clearer calculator names and search terminology
Standardized calculator names around familiar trade and search language, including Wire Ampacity, Conduit Cable Capacity, Conduit Jam Ratio, Offset and Rolling Offset, 3-Point and 4-Point Saddle Bend, and 90° Conduit Stub-Up. Existing URLs remain unchanged.
August 1, 2026
Equipment Grounding Conductor Calculator
Added a scoped 2023 NEC reference workflow for wire-type EGC sizing through 600 A, proportional circular-mil adjustment when phase conductors are increased, branded PDF/CSV reports, shareable project links, and separate phase-plus-EGC handoffs to Conduit Fill and Conduit Size.
August 1, 2026
Wire Ampacity Calculator
Added a transparent 2023 NEC reference workflow for Table 310.16 ampacity, Celsius/Fahrenheit ambient-temperature input, current-carrying-conductor adjustment, terminal limitations, continuous and noncontinuous load comparison, automatic minimum-size and nearby-size comparison with local selected-size details, small-conductor planning limits, branded CSV/PDF output, shareable links, and Voltage Drop handoff.
August 1, 2026
Expanded and organized electrical conductor library
Expanded the electrical-power library to 128 verified products from Southwire, Encore Wire, and Cerrowire, including separately published solid 14, 12, and 10 AWG copper THHN/THWN-2 options. Electrical-only filters now narrow material, insulation, solid or stranded construction, manufacturer, and conductor size.
August 1, 2026
Electrical power conductor library
Added the shared electrical-power category with the initial 59 verified Southwire copper SIMpull THHN/THWN-2 and copper or aluminum XHHW-2/RW90 conductor options from 14 AWG through 1000 kcmil where published. The library supports Conduit Fill, Conduit Size, Conduit Cable Capacity, Conduit Jam Ratio, custom handoffs, and conductor-size handoff to Voltage Drop.
August 1, 2026
Calculator-to-calculator handoffs
Added optional workflow links that transfer compatible conduit, cable, quantity, and fill inputs between Conduit Fill, Conduit Size, Conduit Cable Capacity, and Conduit Jam Ratio without removing or combining the individual calculators.
July 31, 2026
Expanded conduit bending suite
Added three-bend saddle, four-bend saddle, and 90-degree stub-up calculators with unified inputs, responsive diagrams, field marks, available-length checks, manufacturer-neutral custom values, verified optional presets, reports, documentation, structured data, and sitemap coverage.
July 31, 2026
Conduit Offset and Rolling Offset Calculator
Added standard and rolling-offset geometry with imperial and metric inputs, bend multipliers, ideal centerline travel, horizontal run, theoretical shrink, rolling rotation, responsive diagrams, branded reports, CSV export, shareable links, formulas, and field-verification guidance.
July 30, 2026
Quantity-sensitive Conduit Jam Ratio results
Added conduit-fill validation and maximum identical-cable capacity to the Conduit Jam Ratio Calculator. Cable quantity now drives a governing Does not fit result while the report separately explains why the diameter-based jam ratio itself remains unchanged.
July 30, 2026
Scalable calculator navigation
Grouped the calculator menu by purpose, added a prominent All Calculators route and a height-limited mobile-friendly menu, replaced the growing flat footer with organized information groups, and added contextual related-calculator links.
July 30, 2026
Unified custom cable selection
Added a visible Custom / user-entered choice to every cable-manufacturer selector while retaining Custom round cable in every product selector. Either choice now opens the same custom name and outside-diameter workflow.
July 30, 2026
Conduit Jam Ratio Calculator
Added identical-cable jamming-risk screening with shared conduit and cable libraries, custom cable diameter entry, a proportional conduit cross-section, published risk ranges, branded reports, CSV export, and shareable links.
July 29, 2026
Cable Tray Fill Calculator
Added area-fill and single-layer cable tray planning, optional installation allowances, multiple cable groups, generic dimensions, and manufacturer presets for Eaton B-Line, Legrand Cablofil, nVent HOFFMAN, Hubbell, and Snake Tray. Includes tray-width recommendations, proportional diagrams, branded reports, CSV export, and shareable links.
July 29, 2026
Advanced Voltage Drop Calculator
Added DC two-wire, single-phase AC, and balanced three-phase calculations; feeder-plus-branch segments; amperes, watts, kilowatts, VA, and kVA load entry; conductor comparison; parallel-path and temperature modeling; project report fields; branded reports; CSV export; and shareable links.
July 29, 2026
Branded reports and pull-box diagram exports
Added logo-branded printable reports across all calculators, CSV attribution, pull-box SVG and PNG downloads, dimension lines, standard-enclosure guidance, and shareable pull-box calculation links.
July 28, 2026
Pull Box Size Calculator
Added a four-side conduit-entry calculator for multiple conduit runs, straight, angle, and U pulls; proposed inside length, width, and depth review; governing formulas; and an installation-style conduit layout preview.
July 25, 2026
New conduit-capacity engineering article
Added a mathematical comparison explaining why one 4-inch EMT has more internal and 40%-fill area than four 2-inch EMT conduits.
July 25, 2026
Phase 3 engineering resources
Added NEC and BICSI context pages, dataset-generated conduit fill area tables, a resources hub, and the first engineering article.
July 25, 2026
SEO and site-information foundation
Added About, Contact, and FAQ pages; social-sharing metadata; WebSite and FAQ structured data; and improved internal navigation.
July 25, 2026
Protected support and feature requests
Added a support form with optional reply email, Formspree delivery, and Cloudflare Turnstile protection.
July 24, 2026
Expanded conduit and cable planning
Added multiple conduit families, telecommunications cable products, editable multi-conduit plans, compact cable rows, bend planning, and professional PDF/CSV reports.
Latest engineering article
Learn why conduit trade sizes cannot be added together to compare cable capacity.
Suggest the next improvement
Use the protected support form to request a cable product, conduit family, calculator, reference page, or workflow improvement.