Weld Consumable Calculator
Weld area, deposited metal and the electrode you actually need to buy.
Quick answer
With the default inputs: Weld type Fillet weld · Fillet leg size K 6 mm · Plate thickness 10 mm etc.Consumable required 24.7 kg
Edit the inputs below to recalculate.Inputs
Result
Consumable required
24.7kg
| Weld cross-section | 18.0mm² |
| Deposited metal per metre | 0.141kg/m |
| Total deposited metal | 14.13kg |
| Theoretical consumable | 23.55kg |
| Consumable with allowance | 24.73kg |
| Consumable per metre | 0.247kg/m |
| Consumable to metal ratio | 1.75× |
Fillet area uses the theoretical isosceles triangle (A = K²/2) with no reinforcement; real fillets are convex and deposit another 10-20%, so set the extra allowance to 15% for tight procurement. V-groove area is A = b·t + (t−p)²·tan(α/2). Deposition efficiency means kilos of metal deposited per kilo of electrode — about 0.6 for stick welding, the rest becoming stubs, spatter and slag.
Formula
| Fillet area | A = K² ÷ 2 |
| V-groove area | A = b·t + (t − p)² × tan(α ÷ 2) |
| Metal per metre | m = A × 0.00785 (kg/m) |
| Total deposited metal | M = m × weld length |
| Consumable required | G = M ÷ deposition efficiency × (1 + allowance) |
A 6 mm fillet over 100 m at 60% deposition: 18 mm² section, 14.13 kg deposited metal, 24.73 kg of electrode — 0.247 kg per metre.
FAQ
Why is the electrode figure so much larger than the deposited metal?
An electrode never converts fully. In stick welding, stubs, spatter, burning flux and burnt alloying elements waste 35-45%, which is why deposition efficiency sits at 0.55-0.65 — only about 0.6 kg of every kilo lands in the joint. That is normal, not waste. CO₂ gas-shielded welding reaches 0.85-0.95 and saves nearly a third of the consumable.
How is the fillet leg size chosen?
From the thinner plate: equal to plate thickness below 6 mm, about 0.7× for 6-12 mm, and 0.5-0.6× above 12 mm, never below a 5 mm minimum. Both a code minimum (to avoid cold cracking) and a maximum (to avoid burning through thin plate) apply. Oversized legs waste consumable and widen the heat-affected zone and distortion.
How much electrode does a tonne of steelwork need?
Roughly 8-15 kg/t for ordinary portal frames and buildings, 20-25 kg/t for heavy joints with full-penetration welds, and only 4-8 kg/t for light purlins and space frames dominated by thin-plate tacks. The range is so wide it is only good for preliminary ordering — for real quantities multiply this calculator's per-metre figure by the measured weld length.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.