Slope converter
Convert slope between percent, degrees, 1:n and permille, derive the rise and slope length from a horizontal run, and show common engineering limits.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
Percent, degrees, 1:n and permille, plus rise and slope length when a run is given.
Enter a slope to convert
Percent: 0
What this tool does
- Check ramp compliance: an 8.33% slope is the accessible-ramp limit, usually written as 1:12.
- Set out a site from the horizontal run: a 2% slope over 20 m gives a 0.4 m rise and a 20.003999 m slope length.
- Convert an angle-only drawing into a percentage: 5° is about 8.75%.
Example
Input
5.710593
Output
5.710593 角度 → 百分比 10%、角度 5.710593°、1:10、千分比 100‰ 百分比 (%) = 10% 角度 (°) = 5.710593° 坡度比例 = 1:10 千分比 (‰) = 100‰ 水平距离 100 m 时的高差 = 10 m 水平距离 100 m 时的斜长 = 100.498756 m 水平距离 100 m、高差 10 m 时，斜长（实际铺设长度）= √(100² + 10²) = 100.498756 m 常见场景限值（经验值，实际以当地规范为准）： 无障碍坡道（轮椅）：不宜超过 8.333333%（约 4.763642°、1:12） 停车库直线坡道（一般地区）：不宜超过 15%（约 8.530766°、1:6.666667） 停车库直线坡道（雨雪地区）：不宜超过 12%（约 6.842773°、1:8.333333） 小区主干道：不宜超过 8%（约 4.573921°、1:12.5） 公路纵坡（设计上限）：不宜超过 9%（约 5.142765°、1:11.111111） 排水沟纵向坡度（常规）：不宜超过 0.5%（约 0.286477°、1:200） 屋面排水坡度（瓦屋面下限）：不宜超过 33.333333%（约 18.434949°、1:3）
A 10% slope is 5.710593°, 1:10 or 100‰; over a 100 m run the rise is 10 m and the slope length 100.498756 m.
Frequently asked questions
How is the slope percentage defined?
Slope percent = rise ÷ horizontal run × 100%. The denominator is the horizontal distance, not the slope length: 10 m of rise over 100 m gives 10% and an angle of arctan(0.1) = 5.710593°.
How does 1:n map to percent?
n = 100 ÷ percent. 10% is 1:10, 5% is 1:20 and 2% is 1:50. A zero slope has no ratio and is labelled “level”.
Can the angle reach 90°?
No. The slope angle is an arctangent, so it lives between 0° and 90°; 90° would be infinite slope and is rejected.
Can the limits be used for compliance?
They are references. The 1:12 accessible ramp, 15% garage ramp and 9% highway grade come from common practice; always check your local code and its ramp-length requirements.
Keywords：坡度换算百分比转角度坡度 1:n千分比高差斜长无障碍坡道公路纵坡