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New tool releases, updates, and notices, listed newest first.
- 2026.06.25New tool
PoE Power Budget Calculator (IEEE 802.3af/at/bt) is now available
Add powered devices by type and PD class to total the PoE load, then check it against your switch power budget per IEEE 802.3af/at/bt — with utilization, an 80% headroom check, and a port-count check. Choose actual device draw or the conservative PD class reservation. Free, no sign-up, with a printable PDF report.
- 2026.06.24New tool
Insulation Calculator (2021 IECC) is now available
Get the DOE-recommended R-value for your climate zone and assembly — attic, wall, or floor — then convert it to an installed thickness, blown-in bag count or batt area, material volume, and cost across nine insulation materials, with a check for when a wall target exceeds the stud cavity. Free, no sign-up, with a printable PDF report.
- 2026.06.24New tool
Concrete Block (CMU) Calculator (NCMA TEK 14-13) is now available
Estimate a CMU wall from its length and height in one take-off — block count, mortar (masonry cement and sand), core-fill grout, and vertical and horizontal reinforcement for 6, 8, and 12 in units — with opening deductions and a waste allowance. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Stair Stringer Calculator (IRC R311.7) is now available
Enter the total floor-to-floor rise and get the number of risers, the exact riser height, the tread count, total run, stair angle, and the stringer board length — with a built-in IRC R311.7 check on riser height and tread depth. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Ceiling Joist Span Calculator (IRC R802.5.1) is now available
Find the maximum ceiling joist span straight from the IRC R802.5.1 tables — choose the attic use (without storage at 10 psf or limited storage at 20 psf), lumber species, grade, size, and spacing, then get the max span for every joist size and the smallest one that reaches across your ceiling. Pairs with the rafter span calculator to size the roof frame. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Rafter Span Calculator (IRC R802.4.1) is now available
Find the maximum horizontal roof rafter span straight from the IRC R802.4.1 tables — choose the roof live or ground snow load (no snow, 30, 50, or 70 psf), lumber species, grade, size, and spacing, then get the max span for every rafter size and the smallest one that reaches your ridge. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Deck Beam Span Calculator (IRC R507.5) is now available
Size a built-up deck beam straight from the IRC R507.5 table — choose the lumber species and the deck joist span the beam carries, then get the maximum span for every double and triple 2× beam and the smallest size that reaches your posts. Pairs with the joist span calculator to size the whole frame. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Joist Span Calculator (IRC R502.3.1 / R507.6) is now available
Find the maximum allowable floor or deck joist span straight from the IRC span tables — choose lumber species, grade, joist size, and on-center spacing, then check the result against the clear span you need and get the smallest joist size that covers it. Covers living areas (40 psf), sleeping rooms (30 psf), and decks. Free, no sign-up, with a printable PDF report.
- 2026.06.23New tool
Drain Slope Calculator (IPC 704.1) is now available
Calculate drain and sewer pipe slope both ways — find the total fall from a run and pitch, or the slope from a measured drop — shown in inches per foot, percent, and 1:X ratio, and checked against the IPC Table 704.1 minimum grade by pipe size. Free, no sign-up, with a printable PDF report.
- 2026.06.22New tool
Cut and Fill Calculator (earthwork volume) is now available
Estimate cut and fill earthwork with the average end area method — enter cross-section areas along the alignment to get the total cut and fill, the net import or export in cubic yards with swell and shrink factors, and an estimated truckload count. Free, no sign-up, with a printable PDF report.
- 2026.06.22New tool
Drainage Fixture Unit (DFU) Calculator is now available
Add fixtures to total the drainage fixture unit (DFU) load, then get the minimum building drain, branch, or stack size from IPC Table 710.1. Free, no sign-up, with a printable PDF report.
- 2026.06.22New tool
Gas Pipe Size Calculator (NFPA 54 / IFGC) is now available
Size natural gas or propane pipe with the NFPA 54 / IFGC longest-length method — enter the total BTU load and the longest run to get the minimum Schedule 40 pipe size and its capacity in CFH. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Rational Method Calculator (peak runoff) is now available
Estimate peak stormwater runoff with the Rational Method, Q = C·i·A. Build an area-weighted runoff coefficient from multiple surfaces, enter the rainfall intensity and area, get the peak flow in cfs, and carry it straight into the culvert size calculator. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Culvert Size Calculator is now available
Size a round culvert with Manning's equation — get the full-flow capacity in cfs and velocity for a diameter, or the minimum standard pipe size for a design flow, in concrete, corrugated metal, or HDPE. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Ground Wire (EGC) Size Calculator (NEC 250.122) is now available
Size the equipment grounding conductor from the breaker or fuse rating using NEC Table 250.122 — copper and aluminum side by side — and apply the 250.122(B) proportional upsize when the ungrounded conductors are enlarged for voltage drop. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Motor FLC Calculator (NEC 430) is now available
Look up motor full-load current from NEC Table 430.248/430.250 by horsepower and voltage, then get the 125% branch-circuit conductor ampacity (430.22), the maximum protection by device type (430.52), the disconnect rating (430.110), and the overload from a nameplate FLA (430.32). Single- or three-phase, free, no sign-up.
- 2026.06.21New tool
Transformer Sizing Calculator is now available
Enter a load in kVA, kW with power factor, or secondary amps to get the required kVA, the next standard ANSI size, primary and secondary full-load amps, and the NEC 450.3(B) primary overcurrent device — single- or three-phase. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Concrete Calculator is now available
Add slabs, footings, walls, columns, and sonotubes to get the total cubic yards, the number of 40, 60, or 80 lb pre-mix bags, a waste allowance, and the ready-mix cost. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Steel Weight Calculator is now available
Pick an AISC section — W and S beams, channels, angles, HSS, and pipe — and enter the length, or enter custom dimensions for plate, bar, and tube. Get the total weight in pounds and tons with a per-piece breakdown and optional cost. Free, no sign-up.
- 2026.06.21New tool
Rebar Weight Calculator (ASTM A615) is now available
Add bars by size, length, and quantity to get the total weight in pounds and tons from the fixed ASTM A615 bar weights, with a per-size breakdown, an ASTM A615 weight chart, and an optional cost. Free, no sign-up, with a printable PDF report.
- 2026.06.21New tool
Voltage Drop Calculator is now available
Find the voltage drop %, the voltage at the load, and the minimum copper or aluminum wire size to stay within the NEC 3% / 5% recommendation — DC, single-phase, or three-phase. It also shows the longest run a wire size can reach and checks the ANSI C84.1 minimum voltage. Free, no sign-up.
- 2026.06.21New tool
Conduit Fill Calculator (NEC Chapter 9) is now available
Add THHN, XHHW, THW, or RHH conductors and get the minimum trade size and fill % for EMT, IMC, RMC, PVC Sch 40/80, ENT, FMC, and LFMC, using the NEC Table 1 fill limits and Table 4/5 areas. Free, no sign-up, with a printable PDF report.
- 2026.06.20New tool
Wire Size & Ampacity Calculator is now available
Size copper or aluminum conductors from the load using NEC Table 310.16, with 310.15 ambient and conductor-count derating and the 110.14(C) terminal limit. It also reports the maximum overcurrent device per NEC 240.4. Free, no sign-up.
- 2026.06.20New tool
Box Fill Calculator (NEC 314.16) is now available
Add conductors, clamps, support fittings, devices, and grounds to get the required box volume, fill %, pass/fail, and the minimum box size from NEC Table 314.16(A)/(B). Free, no sign-up, with a printable PDF report.
- 2026.06.18New tool
Cable Tray Fill Calculator (NEC 392.22) is now available
Enter cable diameters and quantities to get the fill %, pass/fail, and minimum tray width for ladder, ventilated, and solid-bottom trays — multiconductor (392.22(A)) and single-conductor (392.22(B)). Free, no sign-up, with a printable PDF report.
- 2026.06.17New tool
AWG Wire Size Chart is now available
Cross-reference AWG and kcmil conductor sizes with NEC 310.16 ampacity (copper and aluminum, 60/75/90 °C), cross-sectional area, diameter, and DC resistance. Filter, sort, select rows, and export to CSV. Free, no sign-up.