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MIG/TIG Gas Consumption Estimator - Shielding Gas Flow Rate, Usage & Cost Calculator

Estimate shielding gas consumption in cubic feet per hour, bottles per job, and total gas cost

Free MIG and TIG shielding gas consumption calculator for welding shops, fabricators, and field operations. Shielding gas is one of the most overlooked costs in a welding operation. A shop running two MIG welders at 35 CFH for 6 hours a day burns through a 300-cubic-foot cylinder every 1.4 days - that is over 250 bottles per year at $25-40 per exchange. This calculator helps you estimate gas consumption, plan cylinder inventory, and compare costs between gas supply options. Enter your welding process (MIG or TIG), gas type (75/25 Ar/CO2, 100% Ar, 100% CO2, tri-mix, etc.), flow rate in CFH, number of welding stations, arc-on time percentage, and shift length. The calculator computes total cubic feet consumed per shift, bottles consumed per week, and annual gas cost broken down by cylinder exchange, bulk tank, or microbulk delivery. It also flags when your usage level justifies upgrading from cylinders to a bulk tank - typically around 10-15 cylinders per month. For TIG welding, it accounts for pre-flow and post-flow gas usage that cylinder-based estimates often miss, plus back-purge gas consumption for stainless and titanium work.

Pro Tip: Most shops run their MIG gas flow rate too high. The common setting of 35-45 CFH wastes gas without improving coverage. In a shop environment with no wind, 25-30 CFH provides excellent shielding for most GMAW applications with 0.035 wire. Higher flow rates actually create turbulence at the nozzle that pulls in atmospheric contamination. Save your gas money - turn it down to 25 CFH and look at your welds. If they are clean and porosity-free, you were wasting 30% of your gas.

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MIG/TIG Gas Consumption Estimator
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How It Works

  1. Select Welding Process and Gas

    Choose MIG (GMAW/FCAW) or TIG (GTAW) and select your shielding gas mix. Common choices: 75% Argon / 25% CO2 for mild steel MIG, 100% Argon for aluminum MIG and all TIG, 90% Argon / 10% CO2 for spray transfer MIG, 100% CO2 for deep penetration short-circuit MIG.

  2. Enter Flow Rate

    Input your gas flow rate in cubic feet per hour (CFH). Typical ranges: MIG with solid wire 25-35 CFH, MIG with flux-core 35-45 CFH, TIG 15-25 CFH, TIG back-purge 5-15 CFH. Use the lower end in shop environments and the higher end for field work with light breezes.

  3. Set Welding Schedule

    Enter number of welding stations, shift length in hours, and arc-on time percentage. Arc-on time is the percentage of the shift spent actually welding. Production MIG shops average 25-35% arc-on time; job shops average 10-20%; TIG work averages 15-25%.

  4. Enter Gas Supply Costs

    Input your cylinder exchange cost and cylinder size (the most common sizes are 80, 125, and 300 cubic feet). If you have bulk tank pricing, enter the per-100-CF cost for comparison.

  5. Review Consumption and Cost

    See daily, weekly, and annual gas consumption in cubic feet, number of cylinder exchanges, and total gas cost. The calculator shows the crossover point where bulk gas becomes cheaper than cylinders.

Built For

  • Welding shop managers estimating monthly gas expenses for budgeting
  • Fabrication companies evaluating whether to switch from cylinders to bulk gas
  • Field welding crews calculating how many bottles to load on the truck for a job
  • Purchasing agents comparing gas supplier quotes on a per-cubic-foot basis
  • Lean manufacturing teams identifying gas waste as a cost-reduction opportunity

Frequently Asked Questions

At a typical flow rate of 30 CFH and 30% arc-on time, a MIG welder uses about 9 cubic feet of shielding gas per hour of shift time. Over an 8-hour shift, that is 72 cubic feet per welder. A 300-cubic-foot cylinder lasts about 4 shifts (32 hours) for one welder at these settings. Actual consumption varies with flow rate setting, arc-on time, and whether the welder turns off the gas between welds.
For shop welding with no drafts: 25-30 CFH for 0.030-0.035 wire, 30-35 CFH for 0.045 wire. For light field conditions: add 5-10 CFH. For windy conditions: use wind screens rather than cranking up flow - excessive flow rate creates turbulence and pulls contamination into the weld pool. If you see porosity, check for drafts and leaks before increasing flow. A $20 windscreen solves what $200 of extra gas cannot.
The breakeven point depends on local pricing, but generally: if you use more than 10-15 cylinders per month, a bulk tank saves money. Cylinder gas costs $0.08-0.15 per cubic foot when you factor in exchange fees, demurrage, and delivery charges. Bulk gas runs $0.03-0.06 per cubic foot. A 3,000 CF bulk tank with monthly deliveries typically saves 40-60% on gas cost compared to cylinders. The tank rental or purchase cost is offset within 6-12 months for most shops.
TIG back-purge on stainless steel pipe uses roughly 5-15 CFH of 100% argon, running continuously from before the root pass until the second pass seals the joint. On a 6-inch pipe weld that takes 30 minutes, back-purge uses about 5-7 cubic feet of argon. For large-diameter pipe or long seam welds, back-purge consumption can exceed the welding torch gas consumption. Use dam plugs to minimize the purge volume and save gas.
Pure CO2 costs about 40-60% less per cubic foot than 75/25 argon/CO2 mix. However, CO2 produces more spatter, requires more cleanup time, and uses higher flow rates (35-45 CFH vs 25-35 CFH). When you factor in labor for spatter cleanup and higher flow rates, the total cost difference narrows significantly. For structural and heavy fabrication where appearance is secondary, straight CO2 saves money. For production and appearance-critical work, 75/25 argon/CO2 is usually more economical overall.
Disclaimer: This calculator provides gas consumption estimates based on typical flow rates and arc-on time assumptions. Actual consumption depends on welder technique, equipment condition, gas leaks, and environmental conditions. Gas costs vary by supplier, region, and contract terms. Verify pricing with your gas supplier for accurate cost projections.

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