Welding Cost in Steel Fabrication: Per Metre vs Per Hour

Most fabrication shops quote welding one of two ways, and most do it badly. Some throw a lump "two hours of welding" onto the line and hope. Others have a price-per-metre in their head from a job they did three years ago and apply it to everything. Getting the welding cost in fabrication right is really about choosing the correct basis — per metre or per hour — for the work in front of you, and then deriving a rate that holds up across joints, thicknesses, and finishing. This guide shows how to build both, when each wins, and how to stop the per-metre shortcut from quietly eating your margin.

The two methods are not rivals. A price-per-metre rate card is the fast, repeatable way to quote standard fillet and butt welds on familiar steel. An hourly rate is what you fall back to for fit-up-heavy weldments, awkward positions, and anything the rate card never anticipated. The skill is knowing which one the job calls for — and making sure the per-metre number was built from the hourly cost in the first place.

Why welding refuses a single flat rate

A weld is one line on a drawing, but the cost behind it scales with the cross-section, not the length. Double the fillet leg and you roughly square the deposited metal — so the same metre of weld can cost two minutes or twenty. Three things move the number more than length ever does:

Cross-section. Weld metal per metre grows with the square of the fillet leg, and with the groove volume on a butt weld. A 4 mm fillet and an 8 mm fillet are not "a bit different" — the 8 mm carries roughly four times the metal.
Number of passes. Thin plate is one pass; a 20 mm prepped butt joint is six to ten, each one arc time plus interpass cleaning you pay for.
Operating factor. The welder is not arcing every paid minute. Real arc-on time is typically 20–40% of clocked time once you count repositioning, slag removal, wire changes, and fit checks.

Any rate card that ignores these is a rate card that loses money on the heavy work and overprices the light stuff. The deeper breakdown of these drivers lives in our welding and fabrication cost estimation guide; here we turn them into a price.

Building the per-metre rate (from the hourly rate up)

A per-metre price is not a guess — it is your hourly cost divided across the metres that hour produces. Build it in four steps:

Start from a fully burdened welder-hour rate. Labour, the welding plant, gas and consumables overhead, floor space, and shop overhead, divided by realistically billable hours. If you have not built this number, do it the same way as a machine shop hourly rate.
Estimate deposited weld metal per metre. For a fillet, ≈ (leg² ⁄ 2) × 7.85 g/cm³ × a reinforcement factor (~1.2). A 6 mm fillet is roughly 0.13–0.18 kg/m.
Convert metal to arc time using your process deposition rate (MMA ~1–2 kg/hr, MIG/MAG ~2–5 kg/hr), then divide by your operating factor to get real welder minutes per metre.
Multiply welder minutes by the hourly rate, then add a slice for consumables. That is your cost per metre; apply markup on top.

Worked example, at a €55/hr fully burdened rate and a 30% operating factor: a 6 mm fillet at 0.15 kg/m and 2.5 kg/hr deposition is ~3.6 min of arc, ~12 min of paid welder time per metre — about €11/m in labour before consumables and markup. Do this once per joint-and-thickness combination and you have a rate card.

A starting rate card

Defaults for manual MIG/MAG on mild steel at a €55/hr burdened rate, 30% operating factor. These are calibration starting points, not gospel — log your real times and overwrite them.

Joint and size	Weld metal (kg/m)	Welder time (min/m)	Labour €/m	With consumables €/m
Fillet, 3–4 mm leg	0.05–0.08	6–9	6–8	7–9
Fillet, 6 mm leg	0.13–0.18	10–14	9–13	11–15
Fillet, 8–10 mm leg	0.25–0.45	18–28	17–26	20–31
Butt, single-V, 6 mm	0.20–0.30	14–22	13–20	16–24
Butt, single-V, 12 mm	0.55–0.80	32–50	29–46	35–55
Butt, double-V, 20 mm	1.2–1.8	65–100	60–92	72–110

Read across one row and you can quote a known weld in seconds. The honesty check is in the last two columns: consumables are a small add on steel but climb fast on stainless and aluminium.

When per-metre wins, and when per-hour does

The rate card is fast and consistent, but it silently assumes the weld behaves like the average weld it was built from. That breaks on real jobs. Use this split:

Situation	Quote by
Standard fillets/butts, familiar steel	Metre
Long, repetitive runs (rails, frames)	Metre
Multi-part assembly, heavy fit-up	Hour
Out-of-position, confined, field welding	Hour
Stainless/aluminium with strict heat control	Hour
Distortion-prone thin sheet	Hour
Prototype or one-off you have never run	Hour

The rule of thumb: per-metre prices the arc; it does not price the handling. When fit-up, fixturing, flipping a heavy weldment, or distortion control dominate the job, the metre rate will undersell you every time. Quote those by the hour and estimate the prep explicitly.

The multipliers the rate card forgets

Even on a metre-quoted job, the base rate is for flat, downhand, accessible welding. Real drawings carry conditions that move the number, so keep a short multiplier sheet:

Position. Vertical and overhead welding is slower and lower deposition — add 20–50% to the metre rate. Out-of-position field work, more.
Material. Stainless typically runs 1.3–1.6× mild steel for slower travel, dearer filler, and more cleaning; aluminium often higher again.
Access. Welding inside a box section or around obstructions kills operating factor — treat it as an hourly job.
Intermittent vs continuous. Stitch welds save metal but cost start/stop time; do not price them as a fraction of a continuous run.
Finishing. Grinding welds flush, blending, dressing for paint — these are separate lines, often as large as the weld itself. So are NDT call-outs (dye penetrant, MT, UT, radiography) on the drawing.

Minimum charges and the small-weld trap

A 50 mm tack on a bracket might be 30 seconds of arc, but nobody sets up, cleans, and inspects a part for the price of 30 seconds. Per-metre maths collapses on short welds because setup and handling are fixed costs spread over almost no length. Protect yourself with a minimum weld charge per part and a minimum job charge per order — otherwise small fabrications bleed margin one tack at a time. The same discipline that keeps your markup honest elsewhere applies here; if you are still confusing the two, our margin vs markup guide is worth five minutes.

And remember the pre-weld work that the welding rate never covers: cutting and profiling, bevelling, deburring, and fit-up. Plasma and laser profiling in particular should be costed on their own basis — see laser cutting cost calculation — and added before the weld line, not buried inside it.

Letting the drawing pick the basis for you

The slow part of all this is not the arithmetic — it is reading the drawing. Finding every weld symbol, decoding the fillet leg or groove size, the length, whether it is all-round or intermittent, the field-weld flags and finishing notes, then deciding metre or hour for each. Miss one symbol on a busy weldment and the whole quote is short.

QuoteBuddy reads the technical drawing and surfaces the weld scope for you — it flags the weld symbols, calls out joint types and sizes, and lists every weld so nothing is silently dropped. From there the deterministic estimator applies your rate card, deposition rates, operating factor, multipliers, and minimum charges the same way every time, so two estimators quoting the same drawing land on the same number. The AI does the reading; your rules do the pricing — the split we describe in AI drawing interpretation for quotes.

That is exactly how QuoteBuddy works for fabrication and welding shops: set your welding assumptions once, and every interpreted drawing gets consistent treatment — RFQ to quote PDF in minutes. See the plans and pricing to start a 30-day trial.