長さ変換ツール
メートル、キロメートル、マイル、フィート、インチ、ヤード、海里、光年など23の単位間で長さと距離を変換します。1つの値を入力して単位を選択してから、すべての単位での換算値を一度に表示するか、単一のターゲット単位を選択します。
入力
出力
| 単位 | 値 |
|---|---|
| No data yet | |
ガイド
The Length Converter turns a single distance measurement into its equivalent across 31 units at once. Enter one value, choose the unit it is expressed in, and the tool instantly builds a table showing the same length in meters, kilometers, miles, feet, inches, yards, nautical miles, light-years, and every other length unit in common (and uncommon) use.
Length is the most frequently converted quantity on the web because the world runs on two incompatible systems: metric (meters, based on powers of ten) and imperial/US customary (feet, inches, yards, miles). Add specialist units — nautical miles for sailors and pilots, light-years and parsecs for astronomy, points and picas for typography, hands for measuring horses — and a quick, trustworthy converter earns its keep.
How to use it
- Type the amount you want to convert into the Amount box.
- Pick the unit that amount is in from the Unit list.
- Optionally set the Decimal precision (0 to 10 places) for how the results are rounded.
The results table updates automatically. Very large or very small results (astronomical distances, picometers) are shown in scientific notation so nothing is lost to rounding. Use the copy and download buttons to grab every conversion as CSV.
How many feet are in a meter?
One meter equals approximately 3.28084 feet. This tool computes that conversion (and the reverse) to as many decimal places as you need.
What is the difference between a nautical mile and a statute mile?
A nautical mile (1,852 m) is based on one minute of latitude on Earth's surface and is used in marine and air navigation. A statute mile (1,609.344 m) is the everyday "mile" used for road distances. The two differ by about 15%, which is why mixing them up matters for navigation.
How precise is the light-year conversion?
A light-year is defined here as exactly 9,460,730,472,580,800 meters (the distance light travels in a Julian year), the same constant astronomers use. A parsec is derived independently as roughly 3.26 light-years.
Why does picometer show a value like "999999999999999.9" instead of an exact number?
At extreme scales (femtometers, picometers) the conversion involves numbers far larger than everyday floating-point arithmetic handles exactly — the tiny rounding error is inherent to IEEE-754 double-precision math and shows up long before it would affect any real-world measurement.
Privacy
Every conversion runs entirely in your browser. Nothing you enter is sent to a server, logged, or stored.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/length-converter \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"value": "1",
"fromUnit": "mile",
"toUnit": "all",
"precision": "4"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `length-converter` tool (Length Converter) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.