A full scientific calculator that runs entirely in the page: arithmetic with correct operator precedence, powers, roots, logarithms, trigonometry with DEG/RAD modes, constants like π and e, named variables, and a calculation history you can reuse.
Everything is local — no round-trip to a server for each keystroke — so it works offline and keeps even a long session private. The expression engine is a real parser, so you can type 2 + 3 × 4² and get 50, exactly as written.
Frequently asked questions
Does it follow operator precedence?
Yes: parentheses, then powers, then × ÷, then + −, matching standard math notation.
Can I store values?
Yes — assign to named variables (e.g. x = 5) and reuse them in later expressions.
What is the difference between DEG and RAD?
They set how trig functions interpret angles: DEG treats sin(90) as 1, RAD treats sin(π/2) as 1.
中文说明
一个完全在页面内运行的完整科学计算器：按正确运算优先级做四则运算，支持乘方、开方、对数、三角函数（DEG/RAD 两种模式）、π 和 e 等常量、自定义变量，以及可复用的计算历史。
所有计算都在本地完成——每一步都不经过服务器——因此离线可用，长会话也完全私密。表达式引擎是真正的解析器，直接输入 2 + 3 × 4² 会得到 50，与书写顺序的数学含义一致。
常见问题
遵循运算优先级吗？
遵循：括号 > 乘方 > 乘除 > 加减，与标准数学记法一致。
可以保存数值吗？
可以，给命名变量赋值（如 x = 5），之后的表达式可直接引用。
DEG 和 RAD 有什么区别？
决定三角函数的角度单位：DEG 下 sin(90) = 1，RAD 下 sin(π/2) = 1。