％ 小数转百分数计算器Decimal to Percent Calculator
把小数精确地转换为百分数（乘以 100，移动小数点两位，不产生浮点误差），也可反向把百分数转回小数；可一次转换多个数，并给出最简分数形式。Convert decimals to percentages exactly — multiply by 100 by moving the decimal point two places, with no floating-point error — or percentages back to decimals, several at once, with the simplest fraction too.
使用说明与常见问题How-to & FAQ
「小数转百分数计算器」是什么？What is the Decimal to Percent Calculator tool?
把小数精确地转换为百分数（乘以 100，移动小数点两位，不产生浮点误差），也可反向把百分数转回小数；可一次转换多个数，并给出最简分数形式。Convert decimals to percentages exactly — multiply by 100 by moving the decimal point two places, with no floating-point error — or percentages back to decimals, several at once, with the simplest fraction too.
如何使用「小数转百分数计算器」？How do I use the Decimal to Percent Calculator tool?
在「小数转百分数计算器」中，填写「方向」等参数，结果会随输入实时计算并显示在下方。In the Decimal to Percent Calculator: Fill in "Direction"; results are recalculated instantly as you type.
小数怎么化成百分数？How do I turn a decimal into a percent?
乘以 100，也就是把小数点向右移两位，再加上 %：0.075 → 7.5%，1.2 → 120%。百分数转小数则向左移两位。Multiply by 100 — move the decimal point two places right — and add %: 0.075 → 7.5%, 1.2 → 120%. Going back, move it two places left.
为什么不会出现 7.000000000000001%？Why don't I see 7.000000000000001%?
普通计算器用二进制浮点数相乘，可能产生这种误差；本工具直接移动小数点，结果总是精确的。Ordinary calculators multiply in binary floating point, which can cause that; this tool moves the decimal point directly, so the result is always exact.
计算精度如何？How precise are the results?
「小数转百分数计算器」使用 JavaScript 双精度浮点数（约 15–16 位有效数字），部分功能使用 BigInt 处理大整数。The Decimal to Percent Calculator uses double-precision floating point (about 15–16 significant digits); some features use BigInt for large integers.
「小数转百分数计算器」免费吗？需要注册吗？Is the Decimal to Percent Calculator free? Do I need an account?
「小数转百分数计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Decimal to Percent Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.