How to Estimate Welding Cost (Wire, Time & Labour)

Quoting a fabrication job and not sure what a weld actually costs? Most shops either guess or rely on one experienced estimator’s gut feel — and both lead to jobs that quietly lose money. This guide breaks down how to estimate welding cost properly, in plain terms, so you can price work with confidence.

There are only three things you’re really paying for on any weld: the consumables (filler wire or rod, plus shielding gas), the labour (the welder’s time), and your overhead and margin. Get those three right and your quote is sound. Let’s take them in order.

Step 1: Work out how much weld metal you’re laying

Everything starts with the weight of weld metal you’ll deposit, because cost flows from it.

Weld metal weight comes from the joint geometry:

• Work out the cross-sectional area of the weld from the joint type and size (for a fillet, roughly half the leg length squared; for a groove, from the bevel, gap and thickness).
• Multiply by the total weld length (length per weld × number of welds) to get the volume.
• Multiply volume by the material density (carbon steel is about 7.85 g/cm³) to get the weld weight in kg.

This single number — kilograms of weld metal — drives both your consumable cost and your time.

Step 2: Filler metal and gas (the consumable cost)

You always buy more filler than ends up in the joint, because some is lost to spatter, stub ends and the like. That loss is captured by deposition efficiency, which depends on the process:

• MIG / solid wire: ~90–95%
• Flux-cored: ~80–85%
• Stick (MMA): ~60–65%
• Submerged arc: very high (~99%)

So filler required = weld weight ÷ deposition efficiency, plus a little extra for general wastage. Multiply that by your price per kg of wire or rod for the wire cost.

Don’t forget shielding gas — easy to leave out, but it adds up over a year. Many shops fold it in as a small per-hour or percentage figure.

Step 3: Labour and arc time (usually the biggest cost)

Here’s the one that trips people up. Your arc time — the time the arc is actually burning — is weld weight ÷ deposition rate (kg per hour for the process). For a typical MIG setup that might be only a couple of minutes for a small weld.

But arc time is not the time you pay the welder for. Between welds there’s setup, tacking, repositioning, slag removal, grinding, inspection and walking around the job. The ratio of arc-on time to total time is your operating factor (often only 30–40%). So real labour time is several times the arc time.

Two more adjustments:

• Position: overhead, vertical and pipe welds are slower than flat — add a position factor.
• Access and complexity: awkward, restricted joints take longer.

Then labour cost = labour time × your shop’s hourly rate. On most jobs, labour dwarfs the cost of the wire — which is exactly why underestimating time is what kills margins.

Step 4: Overhead and markup (cost into price)

Cost isn’t price. On top of consumables and labour, add your shop overhead (power, gas, equipment, rent, consumables) and a markup for profit. That gives you the sell price you actually quote.

A worked example

Say you’re pricing a 6 mm fillet weld, 1 metre long, in carbon steel, MIG with solid wire (numbers are illustrative — use your own shop’s rates):

• Weld metal weight ≈ 0.14 kg
• Filler required (90% efficiency + a little wastage) ≈ 0.17 kg → wire cost ≈ $0.60, plus a bit of gas
• Arc time (3.5 kg/hr) ≈ 2–3 minutes… but with a realistic operating factor, labour time ≈ 7 minutes
• Labour at, say, $40/hr ≈ $4.40
• So total cost ≈ $5–6, and with overhead + markup, a sell price around $7

Notice the lesson: the wire was under a dollar, but the labour was most of the cost. Price the time, not the wire.

Common mistakes that blow estimates

• Treating arc time as labour time — the single biggest underestimate.
• Forgetting gas, wastage, tacking, cleaning and rework/NDT.
• Ignoring position and access.
• Using out-of-date wire and labour rates.

Estimate it in seconds

Doing all this by hand for every line of a quote is slow and error-prone. The free WeldIQ Weld Calculator does the whole chain for you: enter the joint geometry, material and process, and it works out weld weight, filler required, arc and labour time, cost, and a sell price — and lets you add multiple welds into a single project total.

A note on accuracy

Treat any estimate as a starting point, not gospel. Real output depends on the process, the WPS, the operator, duty cycle and access — so calibrate the factors (deposition rate, efficiency, operating factor, rates) to your own shop’s actuals over time. Always check final weld sizes against the drawing, WPS and applicable code.