// free-tool
Length Converter
Pick your from and to units and type a value — the result updates live as you type, with a swap button and a quick list of common conversions. It's pure math running locally, so it works instantly and even offline.
no signup · no watermark · unlimited use
Frequently asked questions
How accurate are the conversions?
Conversions use exact standard definitions (e.g. 1 inch = 25.4 mm) computed in double-precision floating point, and results are shown with sensible rounding you can copy at full precision.
Does this tool need an internet connection?
Only to load the page the first time. The conversion itself is pure local math — no network requests are made.
Is this tool really free?
Yes — completely free, with no account, no watermarks and no file limits beyond what your device's memory can handle.
More units tools
Weight Converter
Convert between mg, g, kg, tonnes, ounces, pounds and stone.
Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin.
Area Converter
Convert between mm², cm², m², km², hectares, acres, ft² and in².
Volume Converter
Convert between ml, liters, m³, teaspoons, cups, pints, quarts and gallons (US & UK).
Speed Converter
Convert between m/s, km/h, mph, knots and ft/s.
Time Converter
Convert between milliseconds, seconds, minutes, hours, days, weeks, months and years.
Need custom tools like this in your product?
I build fast, privacy-first web applications with Next.js — these converters run entirely in the browser, and yours can too.