Brachistochrone Calculator
Free online brachistochrone calculator. Enter your values and get instant results with the formula, step-by-step working, a worked example and FAQs — everything runs locally in your browser on Calcton, no signup required.
中文版：最速降线在线计算器
最速降线问题的答案是倒过来的摆线弧：一块冰沿这条曲线滑到墙角比沿任何直线、折线或其他曲线都快。伽利略猜错、伯努利兄弟争胜、牛顿一夜解决——它是变分法诞生的标志性战役。
求解思路：解方程 θ − sin θ = (X/Y)(1 − cos θ) 得到摆线参数角（牛顿迭代），半径 a = Y/(1 − cos θ)，下滑时间 T = θ·√(a/g)。X = 0 时退化为垂直下落，摆线是半圈，T = π√(Y/(2g))，恰与自由落体 √(2Y/g) 一致（时间比 π/√8）。
参考值
X = Y = 1、g = 9.8：θ = 2.4120111439135，a = 0.57291703753175
T = 0.58319278297166 s，直线 = 0.63887656499994 s，比值 = 0.912841094698（摆线快约 8.7%）
X = 0（垂直下落）：T = π√(1/(2g)) = 0.710572 s，与自由落体相同
How to use the Brachistochrone Calculator
- Fill in the inputs with your own numbers — every field shows what it expects.
- The result updates instantly as you type; no "Calculate" click needed.
- Read the result card for the main figure, the step-by-step formula, and practical notes.
Frequently asked questions
Is the Brachistochrone Calculator free?
Yes — all math calculators on Calcton are free, with no sign-up required. Your inputs are processed in your browser and never sent to a server.
Is there a Chinese version of this tool?
Yes. Use the Chinese version link above — it is the same calculator with the interface in Simplified Chinese.
References
Formulas and benchmarks used by this calculator follow these published sources.
KevinContent LeadCalcton Editorial Team · Last updated 2026-09-28
Kevin maintains Calcton's formula verification and content: every calculator cites the standard it implements, worked examples are recomputed programmatically, and health benchmarks follow WHO and international guidelines.
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