MIG Welding Job Cost Estimator

A welding job estimate that keeps the chain intact

A simple price-per-foot rule hides why two jobs with the same length can cost very different amounts. A larger fillet contains more deposited steel per foot. A slower recorded deposition rate increases arc time. Poor access lowers arc-on time. Setup, handling, inspection, crew size, gas price, and package rounding each affect a different part of the estimate. Combining them is useful only when those inputs remain visible.

This calculator therefore composes two independently tested BenchCalcs models. The joint-volume calculator supplies finished deposit weight. The MIG deposition calculator converts that weight into solid-wire feed, arc time, required wire, and whole packages. This page then adds job time, labor, shielding gas, and other direct cost without selecting a procedure or inventing a sales price.

The calculation sequence

1. Finished joint volume: cross-sectional area × physical joint length.
2. Base deposited metal: volume × 0.283 lb/in³ carbon-steel planning density.
3. Planned deposit: base deposit × (1 + the explicit job allowance).
4. Deposited lb/hr: 13.1 × solid-wire diameter² × known WFS × electrode efficiency.
5. Arc hours: planned deposit ÷ deposited lb/hr.
6. Production hours: arc hours ÷ arc-on percentage; then add setup and cleanup.
7. Direct allocated cost: wire consumed + person-hours + gas used + other direct cost.
8. Cash to start: whole wire packages + the same labor, gas, and other direct cost.

Worked planning example

The initial form describes 20 feet of 1/4-inch equal-leg fillet, 10% additional deposited metal, 0.035-inch solid wire at a known 300 ipm, 93% efficiency, and 35% arc-on time. With one person at $65 per loaded hour, 30 minutes of setup, 20 minutes of cleanup, 30 CFH gas, and the illustrative prices shown, the model returns:

• 2.122 lb of base deposited metal and 2.334 lb after allowance.
• 31.3 arc minutes and 2.32 elapsed job hours.
• 2.510 lb of wire, rounded to 1 whole 11 lb spool for purchasing.
• $190.16 in allocated direct cost versus $224.89 in package-rounded cash.
• $9.51 per physical joint foot before overhead, risk, tax, and profit.

The dollar defaults are examples, not market claims. Replace them before using the result. If package balance can serve a later job, allocated cost is the cleaner job-cost comparison. If the shop must buy the spool now, the cash total better describes the immediate outlay.

What arc-on time means here

Arc hours describe only the time solid wire is being deposited. Arc-on percentage expands that into production time for ordinary interruptions such as positioning, cleaning, handling, and minor adjustment. TWI presents 30–45% as a typical range for manual GMAW in its public cost guidance. That broad reference is not a substitute for your own observed jobs: record arc time and clock time on representative work, then use the resulting ratio.

Setup and cleanup stay outside that ratio so they are not diluted on short jobs or double-counted on long ones. Crew size changes person-hours, not the wall-clock duration. Shielding gas uses arc hours rather than elapsed hours, because the model assumes flow while the arc is operating; account separately for purge, pre-flow, post-flow, leaks, and intentional continuous flow when they materially affect the job.

Direct cost is not a customer quote

The result is designed to answer “what does this job directly consume?” It does not cover base metal, cutting, forming, equipment ownership, electricity, rent, administration, travel, permits, tax, inspection, destructive testing, repair probability, contingency, warranty exposure, or profit unless you deliberately add an applicable direct item. A sustainable selling price needs those commercial layers and should never be confused with the calculator's physical and labor baseline.

When this estimator is the wrong tool

• The procedure is not established: obtain the governing WPS or qualified instructions first.
• The filler is tubular or non-steel: the solid-steel deposition equation does not apply.
• The joint geometry is more complex: use a drawing takeoff, CAD volume, or qualified estimate.
• Acceptance or safety is the question: use the applicable code, engineer, inspector, and manufacturer instructions.
• A consequential bid depends on it: validate WFS, efficiency, arc-on time, package price, and labor with current shop evidence.

Sources and methodology

• Lincoln Electric: Gas Metal Arc Welding Guide — The solid-steel GMAW deposition-rate equation, steel density, electrode-efficiency definition, and example efficiency values.
• TWI: Welding Costs — The deposited-metal-first estimating sequence, GMAW consumable losses, typical manual GMAW operating factor, and separation of labor, gas, consumables, and overhead.
• TWI: Welding Costs - Continued — The recommendation to replace generic planning inputs with timed and weighed shop measurements when quote accuracy matters.

Sources and the combined method were reviewed on 2026-08-09. The geometry, solid-wire deposition, package, time, gas, and cost identities are covered by pure-math tests. No WPS variable, code acceptance rule, market labor rate, selling price, or certification claim is inferred.