Lintel Sizing Calculator
Load and size for an RC lintel over a door/window using the masonry triangle rule.
Arching means a lintel carries only the masonry TRIANGLE above it, not the whole wall โ provided there's โฅ L/2 of wall above and sound masonry each side. Bearing: 150โ230 mm per end.
Formula
Lintel Sizing Calculator is a free lintel design for structural engineers, fabricators and site engineers โ 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 Lintel Sizing Calculator
Load and size for an RC lintel over a door/window using the masonry triangle rule. The calculation implements Masonry triangle (60ยฐ) above opening; M = wLยฒ/8; depth โ L/12 (IS 9893 / SP 34 lintel detailing). Arching means a lintel carries only the masonry TRIANGLE above it, not the whole wall โ provided there's โฅ L/2 of wall above and sound masonry each side. Bearing: 150โ230 mm per end.
How to use Lintel Sizing Calculator
- 1Enter Clear opening in m.
- 2Enter Wall thickness in mm.
- 3Enter Slab/other load on lintel in kN/m (0 if slab bears elsewhere or arch action carries it).
- 4Read Design UDL, Design moment, Suggested lintel depth instantly โ no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Lintel Sizing Calculator?
- โImplements the standard formula โ Masonry triangle (60ยฐ) above opening; M = wLยฒ/8; depth โ L/12
- โReference cited on-page: IS 9893 / SP 34 lintel detailing
- โOne-click SI โ Imperial toggle โ values convert in place, physics stays in SI
- โRuns entirely in your browser โ nothing uploaded, free forever
Frequently asked questions
What formula does the Lintel Sizing Calculator use?+
It computes Masonry triangle (60ยฐ) above opening; M = wLยฒ/8; depth โ L/12, per IS 9893 / SP 34 lintel detailing. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Arching means a lintel carries only the masonry TRIANGLE above it, not the whole wall โ provided there's โฅ L/2 of wall above and sound masonry each side. Bearing: 150โ230 mm per end.
Can I use this for real structural design?+
It implements the exact textbook/code formula cited below the result and is ideal for sizing, checking and learning. Final designs should be verified by a qualified engineer against the full code with all load cases.
Is the Lintel Sizing Calculator free to use?+
Yes โ 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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