FREE TOOL
Heat input calculator
Enter volts, amps, weld length and time. Get travel speed and heat input using the same calculation as the G3 app.
Free to use. No calculator account or signup required. Entries stay on this page.
Calculations as dependable as an old 12-valve Cummins.
Calculation method and units
Travel speed = weld length ÷ time. The displayed heat input = voltage × current ÷ travel speed, with units converted to kJ/mm or J/in. No process efficiency factor is applied, matching the app.
This is arc energy before process efficiency. Check the method required by your welding procedure. Average voltage and current may not suit pulsed or complex waveforms. A calculated value does not confirm an acceptable weld.