Free Online Calculators
Professional-grade tools. No signup. No download required.
Electricians
Voltage Drop Calculator
Calculate voltage drop for copper conductors. Single-phase, AWG 14–4/0.
Electricians
Ohm's Law Calculator
Solve for voltage, current, resistance, or power from any two known values.
Carpenters
Stair Rise & Run Calculator
Total rise to riser count, actual riser height, and total run with IRC compliance.
Carpenters
Roof Pitch Calculator
Convert between rise/run, X:12 pitch, and degrees.
Carpenters
Board Feet Calculator
Calculate board footage from dimensions or nominal lumber sizes.
Framers
Stud Count & Spacing
Wall length to stud count at 12", 16", 24", or custom spacing.
Pipefitters
Pipe Offset Calculator
Simple and rolling offsets with SVG diagram.
Electricians
Wire Size Reference
Amperage to minimum wire gauge for common loads.