Welding Gas Calculator | Shielding Gas Usage

Total work time (hr)

Flow rate (CFH)

Arc-on duty during work (%)

Purge/setup allowance (cu ft)

Enter time and gas flow.

Planning tool only. Verify actual material, manufacturer data, code/WPS requirements and project conditions where applicable.

Formula

Gas use ≈ Work hours × CFH × Arc-on duty + purge/setup allowance

Four hours in the shop at 20 CFH does not mean 80 cu ft if the arc is on only 35% of that time. The duty factor is important for planning.

Using PSI instead of CFH, ignoring pre/post-flow, and assuming a cylinder’s stamped size exactly equals usable gas under every condition.

Relevant gear

Tools that match this task — not a random product wall.

Is CFH the same as PSI?

No. CFH is flow rate. PSI is pressure. Use the flowmeter/regulator information appropriate to your setup.

Why does real gas use exceed the estimate?

Pre-flow, post-flow, purge, leaks, setup time and higher flow can all increase consumption.

Can too much gas cause problems?

Yes. Excessive flow can create turbulence and pull air into the shielding zone. Follow process and manufacturer guidance.