Weld Throat Calculator
Theoretical and effective throat from leg sizes — unequal legs handled.
Strength lives in the THROAT, the shortest path through the weld — not the leg you measure with a gauge. Convex caps add zero throat; deep-penetration SAW legitimately adds some.
Formula
Weld Throat Calculator is a free weld throat for welding engineers, fabricators and CWI inspectors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Weld Throat Calculator
Theoretical and effective throat from leg sizes — unequal legs handled. The calculation implements a = l₁·l₂/√(l₁²+l₂²); equal legs → 0.707·s (AWS A3.0 definitions; IS 816). Strength lives in the THROAT, the shortest path through the weld — not the leg you measure with a gauge. Convex caps add zero throat; deep-penetration SAW legitimately adds some.
How to use Weld Throat Calculator
- 1Enter Leg 1 in mm.
- 2Enter Leg 2 in mm.
- 3Enter Extra root penetration (deep-pen processes) in mm.
- 4Read Effective throat instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Weld Throat Calculator?
- ✓Implements the standard formula — a = l₁·l₂/√(l₁²+l₂²); equal legs → 0.707·s
- ✓Reference cited on-page: AWS A3.0 definitions; IS 816
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Weld Throat Calculator use?+
It computes a = l₁·l₂/√(l₁²+l₂²); equal legs → 0.707·s, per AWS A3.0 definitions; IS 816. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Strength lives in the THROAT, the shortest path through the weld — not the leg you measure with a gauge. Convex caps add zero throat; deep-penetration SAW legitimately adds some.
Does this follow AWS/IS welding codes?+
Each tool implements the formula from the cited code or handbook (AWS D1.1, IS 800, ISO/EN). Qualified WPS values always govern over any calculator for code work.
Is the Weld Throat Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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