Guardrail Post Check Calculator
Moment and required section modulus for a railing post under code loads.
A 1.1 m post at 1.5 m spacing under 0.75 kN/m needs ~7.5 cm³ — a 40NB medium pipe just makes it. The BASE CONNECTION (anchors, welds) fails far more often than the post.
Formula
Guardrail Post Check Calculator is a free guardrail load for structural engineers, fabricators and site engineers — 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 Guardrail Post Check Calculator
Moment and required section modulus for a railing post under code loads. The calculation implements M = (w·s)·h; S = M/0.66f_y (IS 875 Part 2 horizontal loads; IBC 1607.9). A 1.1 m post at 1.5 m spacing under 0.75 kN/m needs ~7.5 cm³ — a 40NB medium pipe just makes it. The BASE CONNECTION (anchors, welds) fails far more often than the post.
How to use Guardrail Post Check Calculator
- 1Enter Rail line load in kN/m (IS 875: 0.75 residential · 2.25 assembly? Use local code).
- 2Enter Post spacing in m.
- 3Enter Rail height in m.
- 4Enter Post steel f_y in MPa.
- 5Read Post base moment, Required S instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Guardrail Post Check Calculator?
- ✓Implements the standard formula — M = (w·s)·h; S = M/0.66f_y
- ✓Reference cited on-page: IS 875 Part 2 horizontal loads; IBC 1607.9
- ✓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 Guardrail Post Check Calculator use?+
It computes M = (w·s)·h; S = M/0.66f_y, per IS 875 Part 2 horizontal loads; IBC 1607.9. 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?+
A 1.1 m post at 1.5 m spacing under 0.75 kN/m needs ~7.5 cm³ — a 40NB medium pipe just makes it. The BASE CONNECTION (anchors, welds) fails far more often than the post.
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 Guardrail Post Check 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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