Travel speed from weld length and time. Enter inches or millimetres and seconds or minutes; get IPM and mm/min. An optional second calculation shows arc energy in kJ/in from volts, amps, and that travel speed — with an efficiency toggle only if you want it. Primary focus is travel speed.
Use it when a procedure calls for a travel speed in inches or millimetres per minute, or when you want to see why two welders get different results from the same machine settings.
Mark a measured length, time the bead with a stopwatch, and enter both. The optional section turns the same speed into arc energy for a quick heat check.
Travel speed is length over time, scaled to a per-minute rate. Arc energy is the electrical power delivered for each inch of weld at that speed. Heat input with an efficiency factor is a separate, optional line so this page does not pretend to be a dedicated heat-input calculator.
IPM = (length_in × 60) / time_sec
mm/min = (length_mm × 60) / time_sec
Arc energy (kJ/in) = (V × I × 60) / (IPM × 1000)
Optional heat input = arc energy × η (only when you enable η)
Time in minutes is converted to seconds before the division. Mixing a 12 in length with a time typed as “1” while the dropdown still says seconds invents a sprint — match the unit to the stopwatch.
| Length / time | IPM | mm/min |
|---|---|---|
| 12 in in 60 s | 12.0 | 304.8 |
| 25 in in 120 s | 12.5 | 317.5 |
| 300 mm in 60 s | 11.81 | 300.0 |
| 12 in in 1 min | 12.0 | 304.8 |
Arc-energy check at 12 IPM, 22 V, 180 A: (22 × 180 × 60) / (12 × 1000) = 19.8 kJ/in. With η = 0.8 that optional heat input is 15.84 kJ/in. Each of those rows can be reproduced in the calculator above.
Arc-on time for the length you measured. Pause the clock for stops, restarts, and grinding between passes if you want travel speed for the bead itself. For productivity of a whole joint, time the whole joint and say so on the traveler — this calculator does not know which you meant.
Same speed, different unit. US shops usually quote inches per minute. The calculator always prints both so a metric WPS and an imperial stopwatch can meet in the middle.
Not always. Arc energy here is V×I×time/length with no efficiency. Some codes and WPS sheets multiply by a process efficiency η. This page only applies η when you check the box and type the value your procedure uses. It will not invent 0.8 for MIG or 1.0 for TIG on your behalf.
Only as an optional kJ/in note. Travel speed is the everyday stopwatch math. Heat-input calculations depend on efficiency tables and unit conventions that vary by code. Keeping η optional keeps the arithmetic simple while still letting you see kJ/in when you want it.
Time each pass (or the whole joint) the same way you measure length. Average travel speed across a long joint is fine for a rough check; critical heat-input work wants per-pass numbers and the WPS limits.
Use the voltage your procedure calls for — usually the machine or wire-feeder display at the arc. This page multiplies whatever V and I you type. It does not correct for long leads or a miscalibrated meter.