Superelevation Calculator
Banking required for a curve at design speed (IRC 75% rule included).
India caps banking at 7% (10% hills) so slow trucks don't slide inward. If e+f still can't hold the speed, the radius — not the banking — must grow.
Formula
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Superelevation Calculator is a free superelevation for surveyors, civil engineers and property buyers — 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 Superelevation Calculator
Banking required for a curve at design speed (IRC 75% rule included). The calculation implements e + f = V²/127R (V km/h); IRC: e = (0.75V)²/127R, cap 7% (IRC 38; AASHTO horizontal curves). India caps banking at 7% (10% hills) so slow trucks don't slide inward. If e+f still can't hold the speed, the radius — not the banking — must grow.
How to use Superelevation Calculator
- 1Enter Design speed in km/h.
- 2Enter Curve radius in m.
- 3Enter Side friction factor.
- 4Read Required superelevation, IRC design e (75% speed, no friction) instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Superelevation Calculator?
- ✓Implements the standard formula — e + f = V²/127R (V km/h); IRC: e = (0.75V)²/127R, cap 7%
- ✓Reference cited on-page: IRC 38; AASHTO horizontal curves
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Superelevation Calculator use?+
It computes e + f = V²/127R (V km/h); IRC: e = (0.75V)²/127R, cap 7%, per IRC 38; AASHTO horizontal curves. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
India caps banking at 7% (10% hills) so slow trucks don't slide inward. If e+f still can't hold the speed, the radius — not the banking — must grow.
Are regional land units exact?+
Conversion factors follow state revenue-department values noted on the tool. Units like bigha and katha vary by region, so always confirm the local factor named in your land records.
Is the Superelevation 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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