Control welding overhead with accurate gas costing. Enter flow, time, and cylinder details. Get per‑job, per‑hour, and per‑meter costs instantly on site every time.
| Scenario | Main Flow | Arc Time | Starts | Waste | Usable / Cylinder | Price / Cylinder | Typical Output |
|---|---|---|---|---|---|---|---|
| Shop MIG steel | 18 L/min | 60 min | 20 | 8% | 10 m³ | 85 | Cost per hour and total job cost |
| Site TIG stainless | 12 L/min | 90 min | 35 | 12% | 9 m³ | 110 | Higher starts increase pre/post consumption |
| Pipe purge add‑on | 10 L/min | 30 min | 10 | 15% | 10 m³ | 95 | Purge time can dominate total volume |
1) Gas volume before waste
2) Waste adjustment
AdjustedVolume = RawVolume × (1 + Waste% / 100)
3) Cylinders needed
Cylinders = ceil(AdjustedVolume ÷ UsableVolumePerCylinder)
4) Total cost
Subtotal = (Cylinders × PricePerCylinder) + Delivery + Service + Rental
Total = (Subtotal + Tax) × (1 + Markup% / 100)
Optional cylinder volume estimate (derived mode)
Uses an ideal‑gas approximation to estimate usable volume at standard conditions from cylinder internal volume, fill pressure, temperature, and Z factor.
Shielding gas is a controllable welding overhead that often hides inside “miscellaneous” charges. On site, leaks, long hoses, and wind can raise consumption enough to change profitability. Converting procedure settings into volume and cylinders helps forecast spend, prevent shortages, and compare suppliers. Tracking this line item also supports audits and change orders when consumable assumptions are challenged.
Most MIG and FCAW setups use a steady main flow set on the regulator or flowmeter. Typical ranges are 12–25 L/min in sheltered work and higher outdoors. For imperial meters, that is roughly 25–50 CFH. Enter the flow you actually measure, not the value printed on a procedure sheet.
Arc‑on minutes drive most usage, but starts add pre‑flow and post‑flow volume. Tack‑heavy work and repairs can multiply start counts. With 0.5 s pre‑flow and 8 s post‑flow at 40 starts, you add about 5.7 minutes of extra flow time beyond arc minutes.
Pipe purging and enclosures can consume more gas than the weld itself, so model purge time separately. Standby flow matters when the torch remains live between joints; even 3 L/min over 60 idle minutes becomes 0.18 m³ of added gas that must be paid for.
Suppliers quote cylinder capacity as usable volume at standard conditions. If you only know cylinder size and fill pressure, the derived mode estimates usable volume using an ideal‑gas approach with temperature and a compressibility factor Z. This supports comparing different cylinder footprints when handling limits apply.
Waste captures hose leaks, worn seals, regulator creep, over‑flow, and wind loss. In sheltered bays, 5–8% is common; on open decks it can reach 10–20% unless screens and nozzle shrouds are used. Tune waste by crew, location, and shift to keep estimates realistic.
Gas cost is rarely only “price per cylinder.” Delivery, service, hazmat, and rental can add a meaningful percentage, especially on small orders. Include tax and markup so the output matches your bid structure and the CSV aligns with your cost codes.
Use total volume and cost per unit volume to benchmark suppliers. Cost per hour helps evaluate process changes, such as longer post‑flow for crater protection. Export the PDF for supervisors and the CSV for estimating software, then refine inputs after the first shift.
Choose the unit system first. Metric expects L/min from a flowmeter; imperial expects CFH. Enter the measured regulator setting you use during welding, not a catalog value.
It is the deliverable gas volume at standard conditions that you can actually consume. Suppliers may list it on invoices or spec sheets. If unknown, use derived mode to estimate.
Each start adds pre‑flow and post‑flow time where gas runs without arc time. Many short welds can use more gas than fewer long welds at the same total arc minutes.
Use it only when gas continues between welds, such as when valves are left open or when a purge is maintained. If the torch is shut off between joints, set standby flow to zero.
Start with 5–8% in controlled indoor work. Increase for windy outdoor welding, long hose runs, frequent purges, or known leaks. Adjust after comparing estimates to actual cylinder usage.
Yes. Add delivery and service/hazmat fees, cylinder rental and days, then apply tax and markup. This produces a bid‑ready total that can match your costing method.
No. Exports use the latest successful calculation stored in your session. Press Calculate first, confirm the results, then download the CSV or PDF.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.