Heat Input Calculator
Full ISO/TR 18491 treatment with process efficiency factors and per-step working.
Free Welding CalculatorsProfessional Welding
Professional Welding
Calculations &
Workflow
Accurate
Calculations
Heat Input, Arc Energy, Travel SpeedHeat Input, Arc Energy,
Travel SpeedHeat Input, Arc Energy, Travel Speed
Traceable
Workflows
Save runs, add details, photos and reportsSave runs, add details,
photos and reportsSave runs, add details, photos and reports
Built for
Professionals
For welders, engineers and QA/QC personnelFor welders, engineers
and QA/QC personnelFor welders, engineers and QA/QC personnel
Works on
Any Device
Desktop, tablet and mobileDesktop, tablet
and mobileDesktop, tablet and mobile
Integrated Welding Timer
No need to switch between a Heat Input calculator, stopwatch app or wristwatch. Press Start when welding begins and Stop when it ends. Enter the welding parameters before, during or after welding.
HeatInput records Arc Time and automatically calculates Travel Speed, Arc Energy and Heat Input in one continuous workflow.
Fewer taps. No manual time conversion. No switching between apps.
Measurement Runs
Save, compare and document welding measurements in one clear workflow.
Review key parameters, averages and results, then export, email or report your saved runs.
Why heat input control matters
Cooling rate control
Heat input strongly influences the t8/5 cooling time, which affects HAZ microstructure, hardness and susceptibility to hydrogen cracking.
Mechanical properties
Excessive heat input can promote grain growth and reduce strength and impact toughness, depending on the material and welding conditions.
Procedure qualification
Qualified welding procedures may include heat input limits or related essential variables. Production welding must remain within the applicable WPS and qualification range.
Built into the platform
Arc Energy Calculator
Gross energy per unit length as reported under AWS D1.1 and ASME IX.
Travel Speed Calculator
Derive true travel speed from measured weld length and arc-on time.
Metric & Imperial Units
Switch systems instantly. Every result carries its equivalent conversion.
Instant Results
Live recalculation as you type — no submit buttons, no page reloads.
Engineering Accuracy
Formula, variables, calculation steps and rounding shown for every output.
What would be most valuable to you in HeatInput?
Help us understand which features matter most to you.
Run your first calculation now
No account required. Three welding calculators with detailed results in Metric and Imperial units.