Ladder Length Calculator
Determine the minimum ladder length required by treating the ladder as the hypotenuse of a right triangle. Ideal for painters, roofers, and DIYers planning safe access heights.
Always follow ladder safety practices and local regulations before working at height.
Examples
- Height 3 m, base 1 m ⇒ 3.16 m ladder
- Height 2.4 m, base 0.6 m ⇒ 2.47 m ladder
- Height 4 m, base 1.5 m ⇒ 4.27 m ladder
FAQ
Does the calculator include safety guidelines?
It computes the geometric minimum. Apply the 4-to-1 rule and ladder manufacturer instructions for safe setup.
How much ladder should extend past the roof?
OSHA recommends at least 3 feet (0.9 m) of ladder above the landing surface for stable transitions.
Can I use different units?
Yes. Use consistent units for height and distance (all meters or all feet); the output will match the input units.
Additional Information
- For ladder safety, position the base one foot (0.3 m) away for every four feet (1.2 m) of height—about a 75° angle.
- This calculation assumes flat, stable ground and does not include the extra length needed to extend above a roofline.
- Switch units easily: enter height and distance in feet to receive the ladder length in feet.