Trade calculators and resources for professionals who build things.
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Free Online Calculators
Professional-grade tools. No signup. No download required.
Voltage Drop Calculator
Calculate voltage drop for copper conductors. Single-phase, AWG 14–4/0.
Ohm's Law Calculator
Solve for voltage, current, resistance, or power from any two known values.
Conduit Fill Calculator
NEC Chapter 9 conduit fill — EMT, Rigid, PVC with THHN/XHHW wire types.
Stair Rise & Run
Total rise to riser count, actual riser height, and total run.
Roof Pitch Calculator
Convert between rise/run, X:12 pitch, and degrees.
Pipe Offset Calculator
Simple offsets at 22.5°, 30°, 45°, or 60° with travel and run.
Drainage Slope Calculator
Calculate drop, slope percentage, and pipe elevation for drainage runs.
Gas Line Sizing Calculator
Size natural gas and propane piping by BTU load and pipe length.
Career & Business Calculators
Pay, overtime, apprentice wages, and contractor pricing. No signup. No download.
Construction Overtime Calculator
Federal, California daily, and prevailing wage OT with double-time support.
Union Take-Home Pay Calculator
Gross to net with FICA, taxes, union dues, working dues, and pension.
Apprentice Wage Progression
IBEW, UA, and UBC apprentice pay at each period based on journeyman rate.
Markup vs Margin Calculator
The #1 pricing mistake contractors make — and how to fix it.
Professional Apps — Coming Soon
Built for the jobsite. $9.99 once. No subscription. Ever.
Framing & Carpentry Calculator
$9.99 — one time
Stairs, rafters, board feet, compound miter, and more.
Electrician NEC Calculator
$9.99 — one time
NEC 2023 + 2026 wire sizing, conduit fill, voltage drop.
Pipefitter Calculator
$9.99 — one time
Pipe offsets, rolling offsets, parallel cutbacks, Victaulic tables.
Structural Span Calculator
$7.99 — one time
Joist spans, rafter spans, header sizing, deck beams.
Which NEC Edition Does Your State Enforce?
The most complete NEC adoption tracker online. Updated monthly.
Interactive state-by-state NEC adoption map
Trade Gear Reviews
Reviewed by tradespeople, for tradespeople. Honest pros and cons.
Find the Right App for Your Trade & State
State-specific code requirements, licensing info, and jobsite calculators for every trade across all 50 states.