Groove Weld Volume & Filler Metal Calculator

How it works

Single-V area = (t − land)²·tan(θ/2) + gap × t; reinforcement ≈ ⅔ × cap width × height; weight = area × length × 7.85 g/cm³; consumable = weight ÷ deposition efficiency

Estimating filler metal starts with the cross-sectional area of the groove — a triangle (or two) set by the included angle and depth, plus the rectangle of the root gap and a parabolic cap of reinforcement — multiplied by the length and steel's density of 7.85 g/cm³. Not all of the consumable you buy ends up in the joint: stick electrodes lose 35–40% to stubs, slag and spatter, flux-cored wire around 15%, solid MIG wire only about 5%. Because the area grows with the square of the depth, a double-V or U prep on thick plate saves far more than it costs in machining, and reducing a 60° angle to 45° with a backing strip is another classic saving. Real jobs add 10–20% for over-welding and repairs.

Worked example

A 20 mm plate with a 60° single-V, 3 mm gap and 2 mm land has a groove of 18²·tan 30° + 3 × 20 = 247 mm²; a 2 mm cap over the 23.8 mm face adds 32 mm², so 12 m of seam holds 3.35 L of weld metal — 26.3 kg — needing 27.7 kg of solid MIG wire (~$125) or about 42 kg of stick electrodes.

Frequently asked questions