Ladder Angle Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
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Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the ladder length and the vertical height it reaches.
- Read the angle, base distance and safety check.
How it works
Angle = arcsin(height ÷ ladder length); base distance = √(length² − height²). The safe zone is about 75°.
Worked example
6 m ladder reaching 5.5 m. ≈ 66° — base 2.4 m out.
Common mistakes
- Setting the ladder too upright (tip-back risk) or too shallow (slide-out risk).
- Ignoring the 4:1 rule — 1 m out for every 4 m of height.
Frequently asked questions
What angle should a ladder be?
About 75° — the '4:1 rule': place the base 1 m out for every 4 m of working height. Always follow site safety rules.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.