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任何单位，即时换算

12 个分类 · 100+ 单位 · 1135 个换算对。从下方常用换算中选择，或使用实时计算器。

metre
foot
1 m = 3.2808ft
试试： 1 kg → lb · 0 °C → °F · 1 GB → MB · 30 MPG → L/100km

离线优先 · 中英双语 · 开放换算引擎

Length 13 units Temperature 5 scales Data 12 prefixes PNG compressor no upload

使用步骤

  1. 1

    选两个单位

    从同一分类任选两个单位——米↔英尺、°C↔°F、GB↔MB，等等。

  2. 2

    输入数字

    在任一侧输入任意数字，另一侧即时更新——无需提交按钮。

  3. 3

    读取结果

    拿到精确值，外加 10 行参考表、常见问题、相关换算。

免费工具，不上传，不追踪

一键即用的小工具，完全在你的浏览器里运行。文件不离开你的设备。

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PNG 在线压缩

在浏览器里拖一下就压缩 PNG。Lossless Zlib 优化，不上传、无分析、无需账号。

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通用单位计算器

从同一分类任选两个单位。在任一侧输入数字，另一侧即时更新。

打开 →

按分类浏览

本站每个单位都属于下列分类之一。单位详情页解释定义、给出换算表，并链接到热门换算对。

Length
13 units · base: m
Distance, height, width — anything that measures how long something is. SI base unit: the metre (m).
Mass
10 units · base: kg
How much matter is in something. Differs from weight (which is force). SI base: kilogram (kg).
Temperature
5 units · base: K
How hot or cold something is. Conversions are affine — there is an offset, not just a multiplier.
Area
9 units · base: m²
Size of a 2-D surface. SI base: square metre (m²).
Volume
14 units · base: L
Space occupied by a 3-D object. SI base: litre (L) for everyday use; cubic metre (m³) for SI.
Speed
6 units · base: m/s
Distance per unit time. SI: metre per second (m/s).
Time
12 units · base: s
Duration. SI base: the second (s).
Data
12 units · base: B
Digital information size. SI: the byte (B). Note the difference between decimal (KB=1000) and binary (KiB=1024) prefixes.
Energy
10 units · base: J
Capacity to do work. SI base: joule (J). Also commonly expressed as calories, kWh, BTU.
Pressure
8 units · base: Pa
Force per unit area. SI base: pascal (Pa).
Angle
6 units · base: rad
Rotation or turning. SI base: radian (rad).
Fuel Economy
4 units · base: L/100km
Distance per unit of fuel, or its reciprocal (fuel per distance). Base: litres per 100 km.

热门换算

搜索量最大的单位对。点击查看完整换算表、公式与常见问题。

meter → foot foot → meter kilometer → mile mile → kilometer inch → centimeter centimeter → inch mile → foot yard → meter kilogram → pound pound → kilogram gram → ounce ounce → gram celsius → fahrenheit fahrenheit → celsius celsius → kelvin liter → gallon gallon → to liter → milliliter square → to square → to hectare → acre acre → hectare kilometer → hour mile → hour knot → mile knot → kilometer mach → kilometer hour → minute minute → second day → hour week → day year → day byte → kilobyte kilobyte → byte kilobyte → kibibyte kibibyte → kilobyte gigabyte → megabyte terabyte → gigabyte megabyte → mebibyte gigabyte → gibibyte

查看全部换算对

文章与解读

Reference

What is a unit? A practical guide

Why every measurement needs a unit, the difference between base and derived units, and why SI exists.

6 min Data

Why KB and KiB are different — and why it matters

Disk drives advertise GB, but your OS reports GiB. This article explains the 1000-vs-1024 divide.

5 min Length

Metric vs Imperial: which countries still use imperial?

A quick map of who uses which — and where metric beats imperial at scale.

4 min Temperature

Celsius to Fahrenheit explained — the formula and the intuition

F = C × 9/5 + 32. Here is why that formula is what it is.

4 min

查看全部文章

常见问题

What is unitbox?

unitbox is a network of unit-conversion pages: every popular unit gets a detail page, and every popular pair gets a converter. Length, mass, temperature, area, volume, speed, time, data, energy, pressure, angle, and fuel-economy.

How accurate are the conversions?

All conversions use the standard SI conversion factors. For mass, length, time, the values match NIST to the precision shown. Temperature uses the affine offset/scale formulas; the precision is 2 decimal places by default.

What is the difference between KB and KiB?

KB (kilobyte) = 1000 bytes — the SI decimal prefix. KiB (kibibyte) = 1024 bytes — the binary prefix designed to remove ambiguity. Disk drives advertise KB; RAM and operating systems often show KiB. For more, see the learn page on data units.

How do you handle fuel economy?

We treat fuel-economy as a reciprocal quantity. The base unit is L/100 km (lower is better); MPG-US, MPG-UK, and km/L are stored as reciprocals. Converting 30 MPG-US gives 7.84 L/100km.

Does this work offline?

Yes — every page is statically generated. Once loaded, the converter widget runs without a network roundtrip. Bookmark any pair page.

Can AI agents cite unitbox?

Yes — point your agent at https://unitbox.online/llms.txt and /openapi.json. The site is built to be AI-friendly by default: JSON-LD, schema.org, and a machine-readable product brief.

相关搜索

metres to feet celsius to fahrenheit kg to lbs miles to km litres to gallons inches to cm GB to MB hours to minutes psi to bar joules to calories hectares to acres kelvin to celsius knots to mph degrees to radians mpg to l/100km
开源 · OpenAPI · Agent 技能

unitbox API · 让任何 AI Agent 都能调用换算

为 Claude、Cursor、Codex 以及所有支持 HTTP 的 AI Agent 提供的开放换算引擎。免费、MIT 协议、无速率限制。

$ curl 'https://api.unitbox.online/v1/convert?from=meter&to=foot&value=1'
OpenAPI 3.0 MIT licensed 完全开放
GitHub npm OpenAPI 规范 LLM 指南