Shielding Gas Consumption Calculator
Enter your gas flow rate in CFH to find how much shielding gas a weld uses and how long a cylinder will last. Handy for MIG and TIG cost estimates and job planning.
How to calculate shielding gas use
- Enter the gas flow rate in cubic feet per hour (CFH).
- Enter your arc-on welding time to get gas used, or a cylinder size for run time.
- Read the gas consumed and the estimated cylinder duration.
Examples
Gas used in an hour
35 CFH, 60 minutes welding
35 cubic feet used
Cylinder run time
35 CFH, 250 cu ft cylinder
About 7.14 hours of arc time
Frequently asked questions
How is shielding gas consumption calculated?
Gas used equals flow rate in CFH times welding time in hours, so minutes are divided by 60 first. At 35 CFH, one hour of arc time uses 35 cubic feet. This is an exact ratio at steady flow.
How long does a gas cylinder last?
Cylinder duration in hours equals cylinder capacity in cubic feet divided by the flow rate in CFH. A full 250 cu ft bottle at 35 CFH gives about 7.1 hours of continuous arc time.
Is this arc-on time or shift time?
It is arc-on time, the minutes gas is actually flowing. Real shifts include setup, tacking and idle periods, so a cylinder usually lasts more wall-clock time than the figure here.
What is a typical flow rate?
Many MIG jobs run around 20 to 40 CFH and TIG around 10 to 25 CFH, higher with bigger cups or in drafts. Use the value from your procedure or flowmeter for an accurate result.
Why does my gas run out faster?
Leaks, long pre-flow and post-flow, drafts that need higher flow, and surge at arc start all add up. Check fittings and set the flowmeter to the lowest rate that still gives clean welds.
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