Safe Ladder Angle Calculator (4-to-1 Rule)
Calculate the correct ladder angle and base distance using the 4-to-1 safety rule. Prevent falls and injuries.
The 4-to-1 Rule
For safe ladder placement: set the base 1 foot from the wall for every 4 feet of height. A ladder reaching 20 feet should have its base 5 feet from the wall. This creates a 75° angle — the sweet spot where the ladder is stable against both sliding out (too shallow) and tipping backward (too steep). OSHA requires this angle for workplace ladder use.
Ladder Safety Statistics
Falls from ladders cause 300+ deaths and 130,000 emergency room visits per year in the US. Most fatal falls are from heights under 10 feet. The top causes: wrong angle (too steep or shallow), overreaching to the side, climbing with tools in hands, and using a damaged ladder. Following the 4-to-1 rule and maintaining three points of contact prevents the vast majority of ladder accidents.
The "belt buckle rule" prevents the most common ladder accident — overreaching. Your belt buckle should never extend past the side rails. If you need to reach further, climb down and move the ladder. This takes 2 minutes; a fall takes 2 months to recover from.
