계단 수, 보행 높이, 보폭 깊이, 현 길이, 계단 각도를 즉시 계산합니다. 미국식과 미터법을 지원합니다.
Our free stair calculator helps builders, contractors, and DIY enthusiasts design safe and comfortable stairs. Enter your total rise (vertical height) and total run (horizontal depth), set your preferences, and get instant calculations for step count, riser height, tread depth, stringer length, and stair angle. All calculations follow standard building codes and comfort formulas.
The ideal stair angle for residential stairs is between 30° and 37°. Steeper angles (up to 45°) are used for stairs in tight spaces like attics. Commercial stairs typically stay between 30° and 35°.
The 2R + G formula is a comfort rule where R = riser height and G = tread depth (going). The ideal range is 550–700 mm (22–28 inches). This ensures stairs are comfortable and safe to walk on.
Standard riser height is 7–7.75 inches (175–200 mm). Standard tread depth is 10–11 inches (250–280 mm). These dimensions comply with most building codes and provide comfortable stairs.
Stringer length is calculated using the Pythagorean theorem: √(total rise² + total run²). This gives you the diagonal length of the stair stringer board needed.