MIG Wire Size Chart and Calculator
See every MIG wire diameter in inches and mm, and work out how much wire is on a spool and how long it lasts at your wire feed speed.
The MIG wire size chart on this page is a free calculator that works out how much MIG welding wire is on a spool, how long the spool lasts and how much metal you deposit per hour. It runs in your browser with no sign-up, so you can use it on a phone or a computer. You choose the material, wire size, spool weight and wire feed speed, and the results update as you type. The page also includes a table of 12 common wire sizes for the material you pick.
It is also a MIG wire size guide: the table compares every size side by side.
How to use the MIG wire size chart tool
- Choose the material from the list: mild steel, stainless, aluminium or silicon bronze. Each has a typical density, which the tool uses in its weight calculations.
- Choose the wire diameter. You can pick an inch size (0.023 to 1/16 in) or a metric size (0.6 to 1.2 mm).
- Choose the spool weight: 2, 10, 11, 33 or 44 lb, or 1, 5 or 15 kg. Pick a custom weight if your spool is different.
- Set the wire feed speed and its unit: in/min, m/min, ft/min or mm/s.
- Open More options if you need to change the deposition efficiency (default 95 %) or enter a density override.
- Read the results: wire on the spool in feet and metres, arc-on time per spool, grams per metre, feet per pound, metres per kilogram, pounds per 1000 ft, and wire used and metal deposited per hour.
- Open How it was calculated to see the formula and each step with your numbers.
Use Copy result to copy the result lines with a link. Copy link copies the page address, which stores all your inputs, so opening it later restores the same calculation. Print / save as PDF prints the inputs, results, calculation steps and the date.
The presets show 0.035 in on an 11 lb spool, 0.045 in on 33 lb, 1.2 mm on 15 kg and aluminium on 1 kg.
What are the MIG wire sizes in inches and mm?
The inch sizes are 0.023, 0.030, 0.035, 0.040, 0.045, 0.052 and 1/16 in (0.0625 in). The metric sizes are 0.6, 0.8, 0.9, 1.0 and 1.2 mm. Inch and metric wires are separate nominal sizes, so they do not convert exactly into each other.
How much wire is on a MIG spool?
Divide the spool weight by the weight of one metre of wire. Weight per metre equals density × π × d² ÷ 4, where d is the wire diameter. For 0.035 in mild steel that is 4.87 g/m, so an 11 lb spool (about 4,990 g) holds about 1,024 m, or 3,360 ft.
How long does a spool of MIG wire last?
Arc-on time per spool equals the length on the spool divided by the wire feed speed, using the same units for both. A 3,360 ft spool fed at 300 in/min gives 40,320 in ÷ 300 in/min, which is 134 min, or 2 h 14 min. This counts only the time the arc is running.
How many feet of wire per pound?
Divide 453.59 g by the grams per metre, then convert metres to feet. For 0.035 in mild steel, 453.59 ÷ 4.873 is about 93 m, or about 305 ft per pound. Aluminium wire of the same size weighs about a third as much as steel, so it gives roughly three times as many feet per pound.
Is 0.035 the same as 0.9 mm wire?
No. 0.035 in equals 0.889 mm, which is slightly smaller than 0.9 mm. The two sizes are close enough that they are often used in similar work, but they are separate nominal sizes, so check the size printed on your spool.
How do you calculate deposition rate?
Wire used per hour equals wire feed speed × 60 × weight per length, using matching units. Metal deposited per hour equals wire used × deposition efficiency. For 0.035 in mild steel at 300 in/min (7.62 m/min), the wire used is about 457 m/h × 4.87 g/m, or about 2.23 kg/h. At the default 95 % efficiency, about 2.12 kg/h is deposited. At the same feed speed, a thicker wire deposits more metal per hour.
Sources
Checked October 2026:
- Canada Welding Supply, ER70S-6 MIG wire for 0.023–0.045 in and 0.6–1.2 mm wire and 2/11/33/44 lb spools; Lincoln SuperArc L-56 listing (weldingmart) for 0.052 in, 1/16 in and 10 lb spools
- Densities: steel 7.85 (Wikipedia, Density), stainless 8.0 (Quickparts 304 data sheet), aluminium 2.70, silicon bronze 8.53 g/cm³ (Austral Wright C65500)
- Mass per length = density × π d² ÷ 4; NIST SP 811 unit factors
For estimation; verify critical designs against the applicable standard.
Worked examples
| Input | Result |
|---|---|
| 0.035 in Mild steel (7.85 g/cm³), 11 lb spool | 4.873 g/m, 3,360 ft (1,024 m) on the spool, lasts 2 h 14 min at 300 in/min |
| 0.045 in Mild steel (7.85 g/cm³), 33 lb spool | 8.055 g/m, 6,097 ft (1,858 m) on the spool, lasts 3 h 3 min at 400 in/min |
| 1.2 mm Mild steel (7.85 g/cm³), 15 kg spool | 8.878 g/m, 5,543 ft (1,690 m) on the spool, lasts 3 h 31 min at 8 m/min |
| 0.035 in Aluminum (2.70 g/cm³), 1 kg spool | 1.676 g/m, 1,958 ft (596.7 m) on the spool, lasts 1 h 7 min at 350 in/min |
| 1/16 in (0.0625 in) Stainless steel (8.0 g/cm³), 44 lb spool | 15.83 g/m, 4,135 ft (1,260 m) on the spool, lasts 5 h 31 min at 150 in/min |
Calculated by the tool above with these values.
Frequently asked questions
Can I use the tool for aluminium wire?
Yes. Choose aluminium from the material list, and the tool uses its typical density of 2.70 g/cm³. For example, 0.035 in aluminium at 1 kg gives about 597 m on the spool.
Does the tool tell me which wire size or settings to use for my plate thickness?
No. The tool does not recommend a wire size or settings for a plate thickness. Use the welder’s and wire maker’s charts for that.
Can I use the results in quotes or shop paperwork?
Yes. Results may be used in commercial work, such as quotes, welding procedure planning, shop paperwork and reports, without attribution.
Do I need to install anything or make an account?
No. Everything runs in the browser, and nothing you enter is uploaded.
Can I change the density if my wire is different?
Yes. Under More options, enter a density override to replace the typical density for the material you selected.
Is there a MIG wire size guide for each size?
The table under the result is a MIG wire size guide by weight: every inch and metric size with feet per pound and metres per kilogram for the material you pick.
How long is wire on a 2 lb spool?
For 0.030 in steel a 2 lb spool holds about 830 ft (253 m); pick the 2 lb spool and your size to see the exact length.
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