Enter joint data
Tip: use fillet options for angle joints, butt options for groove seams, pipe mode for circumferential welds, and frame mode for perimeter welding.
Plotly graph
The chart scales cumulative face area and weld volume with the number of identical joints.
Example data table
| Case | Joint type | Main dimensions | Typical use |
|---|---|---|---|
| 1 | Single fillet | Length 1200 mm, leg 8 mm | Stiffener to plate connection |
| 2 | Double fillet | Length 900 mm, leg 6 mm | Bracket welded both sides |
| 3 | Butt plate | Length 1500 mm, thickness 12 mm, bevel 60° | Plate splice in fabricated beam |
| 4 | Pipe circumferential | Diameter 400 mm, wall 10 mm | Pipe spool field joint |
| 5 | Rectangular frame | 1500 × 900 mm, fillet 6 mm | Door frame and support assembly |
Formula used
Single fillet weld
Cross-section area = 0.5 × leg²
Effective throat = 0.707 × leg
Face area = seam length × leg
Volume = cross-section area × effective seam length
Double fillet weld
Use the same fillet formulas, then double the seam length for both sides.
Butt and pipe groove welds
Top groove width = root gap + 2 × thickness × tan(bevel angle ÷ 2)
Groove area = thickness × (root gap + top groove width) ÷ 2
Cap area ≈ 0.5 × reinforcement × top groove width
Volume = (groove area + cap area) × effective seam length
Frame welds
Perimeter = 2 × (width + height)
Effective seam length = perimeter × quantity × welded sides
Mass and time
Net volume = gross volume × (1 + allowance %)
Mass = net volume × density
Arc time = mass ÷ (deposition rate × efficiency)
How to use this calculator
- Select the joint model that matches your construction detail.
- Choose the input unit before entering dimensions.
- Enter seam dimensions, groove data, or frame size.
- Add fabrication assumptions such as density, allowance, and deposition rate.
- Press calculate to show welding results above the form.
- Use CSV or PDF download buttons to export the summary.
Frequently asked questions
1) What does welding area mean here?
This page reports weld face area and fusion area. Face area helps with coating and inspection estimates. Fusion area helps compare penetration or bonded section assumptions for each joint type.
2) Why is double fillet area larger?
A double fillet weld places weld metal on both sides of the joint. The calculator doubles effective seam length, so area, volume, mass, and estimated time all rise accordingly.
3) How is butt weld area estimated?
The butt model treats the groove as a trapezoid and adds a simple reinforcement cap. It is useful for planning and budgeting, though your WPS may require a more exact profile.
4) How is pipe weld length found?
Pipe seam length is calculated from circumference, using π multiplied by outside diameter. That length becomes the basis for weld face area, fusion area, and weld metal volume.
5) Should I add an allowance factor?
Yes. Real jobs include starts, stops, tie-ins, losses, and extra reinforcement. The allowance factor increases calculated volume before mass and time are estimated.
6) What density should I enter?
For carbon steel filler, 7.85 g/cm³ is a common planning value. Stainless and nickel alloys differ, so change density when your filler metal is not standard steel.
7) What does arc efficiency affect?
Arc efficiency reduces the effective deposition output. Lower efficiency means more hours are needed for the same weld mass, which is useful when planning crew time or machine loading.
8) Can I mix metric and inch jobs?
Yes. Select the input unit first, then enter all dimensions in that unit. Results are displayed in matching length, area, and volume units for consistency.