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Welding and fabrication calculators

Heat input, fillet weld volume and filler weight, sheet-metal bend allowance and flat length, mitre and slope converters, pipe elbow cuts, and speed and gas-flow unit converters. Arithmetic only: your welding procedure specification governs.

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Planning aid, not a procedure. These calculators do arithmetic on numbers you enter. They do not give welding parameters, procedure specifications or code-qualified settings: the welding procedure specification (WPS), the applicable code or standard, and the qualified person on site govern. Verify against the manufacturer's data.

1. Heat input

Arc voltage, V

Current, A

Travel speed

Travel speed unit

Process (sets a typical efficiency, editable)

Process efficiency (0 to 1)

Heat input (kJ/mm) = V × A × 60 ÷ (travel speed in mm/min × 1000) × efficiency. The efficiency values shown are the commonly published typical figures (for example in EN 1011-1); other standards use different conventions and your WPS or code states which applies. Use the actual measured values from the run.

2. Fillet weld volume and filler weight

Units

Leg 1

Leg 2 (same as leg 1 for an equal fillet)

Total weld length

Weld metal density, kg/m³ (editable)

Deposition efficiency (0 to 1, your filler's data)

Volume of a triangular fillet = ½ × leg 1 × leg 2 × length. Convexity (reinforcement), root penetration, gaps and spatter are not included, so real consumption is higher. Filler needed = weld metal weight ÷ deposition efficiency; take the efficiency from the consumable maker's data (it is a percentage of the consumed material that ends up in the weld; the example value is only a placeholder).

3. Sheet-metal bend allowance, bend deduction and flat length

Bend angle (degrees the sheet is turned; 90 for an L)

Material thickness T

Inside bend radius R

K-factor (typical range about 0.33 to 0.5)

Leg A, measured on the outside (to the virtual sharp)

Leg B, measured on the outside

Use one unit throughout (all the results are in that unit). BA = angle(radians) × (R + K × T). Outside setback = tan(angle/2) × (R + T); bend deduction BD = 2 × setback − BA; flat length = A + B − BD. The K-factor depends on material, thickness, radius, tooling and method: 0.33 to 0.5 is a typical working range, so confirm it with a test bend or your press-brake data.

4. Angle, slope and mitre converters

Angle ↔ slope

Enter

Value

Mitre cut angles

Corner (included) angle between two members, degrees

Or: sides of a regular polygon frame

5. Two-piece pipe elbow (and segmented elbows)

Total change of direction, degrees (90 for a 90° elbow)

Mitre joints (1 = two pieces, 2 = three pieces, ...)

Pipe outside diameter (any unit)

Each mitre joint turns the pipe by (total angle ÷ joints); each pipe end is cut at half of that, measured from a square cut. On each mitred end the long side is longer than the short side by OD × tan(joint angle ÷ 2). The end pieces of a multi-joint elbow have one mitred end; the middle pieces have two. Lengths along the pipe, fit-up gap and the root face are for you to add.

6. Unit converters

Inches per minute (IPM)

Millimetres per minute

Millimetres per second

Gas flow, litres per minute (L/min)

Gas flow, cubic feet per hour (CFH)

Edit any box; its partner updates. 1 in = 25.4 mm; 1 ft³ = 28.3168 L, so 1 L/min = 2.1189 CFH. Flow rates for a job come from your WPS or the consumable maker, not from this page.