Ladder Angle Calculator
Safe ladder base distance (4-to-1 rule), reach and length.
About this tool
Enter your ladder's length to get the safe base distance and how high it reaches. Check the angle for any base distance, or enter a height to step onto to find the ladder length needed.
Setting a ladder at a safe angle
The standard advice for leaning ladders is the 4-to-1 rule: for every 4 units of height up to where the ladder rests, the base should be 1 unit out from the wall. That's an angle of about 75ยฐ to the ground. Set it shallower and the foot can slip outwards; steeper and the ladder can tip backwards, especially as you climb. A 6 m ladder placed correctly has its base about 1.46 m from the wall and reaches about 5.8 m up. If you're stepping off onto a roof or platform, the ladder should extend about 1 m (3 ft) above the landing point, so reaching a 4 m gutter safely takes a ladder of at least 5.1 m. A quick field check: stand with your toes at the ladder's feet and stretch your arms straight out; your hands should just reach the rungs. Honest limits: angle is only part of ladder safety. Secure the top or have someone foot it, use firm level ground, keep three points of contact, never overreach, and follow the manufacturer's instructions and local work-at-height rules. Not safety advice. The Pythagorean theorem calculator and the stair calculator are related.
Frequently asked questions
What is the 4-to-1 rule for ladders?
Place the base 1 unit out from the wall for every 4 units of height, about 75ยฐ.
How far from the wall should a 6 m ladder be?
About 1.5 m (1.46 m to be exact at 76ยฐ).
How far should a ladder extend above a roof?
About 1 m (3 ft) above the landing point, so you have something to hold.
What angle should a ladder be at?
About 75ยฐ to the ground.
Is my data sent anywhere?
No. Everything is calculated in your browser, and nothing is stored or sent.