Length Converter — Free Online Tool
Convert km, miles, metres, feet, inches & more instantly. · No signup · Works on mobile
100% private: your data is processed in your browser. Nothing is uploaded to our servers.
How to use the length converter
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Enter the length value you want to convert.
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Choose the unit you have and the unit you need.
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Read the converted value instantly — swap direction with one click.
What does this tool do?
This free length converter switches between all common distance units — millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles — instantly. Type a value, pick your units, and get results accurate to six significant figures, plus a handy chart of everyday equivalents.
How does the length converter work?
All conversions route through the metre using internationally fixed ratios: 1 inch = 25.4 mm exactly (defined in 1959), 1 foot = 0.3048 m, 1 mile = 1,609.344 m. Because the ratios are exact, chained conversions never accumulate rounding errors.
Frequently Asked Questions
How many feet are in a metre?
One metre equals 3.28084 feet, or about 3 feet 3.37 inches. Going the other way, 1 foot = 0.3048 m exactly. For quick estimates: a metre is roughly one large step, and 10 metres is about 33 feet.
How do I convert kilometres to miles in my head?
Multiply by 0.6 for a quick estimate (or use the Fibonacci trick: 5 km ≈ 3 mi, 8 km ≈ 5 mi, 13 km ≈ 8 mi). Precisely, 1 km = 0.621371 miles, so a 10K race is 6.21 miles and a marathon (42.195 km) is 26.2 miles.
Is the length converter really free?
Yes — 100% free with no hidden charges, trial limits, or premium tiers for core features. You don't need to create an account or enter an email address. The site is supported by non-intrusive display ads, which keeps every tool free for everyone.
Is my data private when using the length converter?
Completely. The length converter runs entirely in your browser using JavaScript — nothing you type or upload is sent to our servers. When you close the tab, your data is gone. This makes it safe for confidential documents, financial figures, and personal information.
Does the length converter work on mobile phones?
Yes. The length converter is built mobile-first and works on any phone or tablet with a modern browser — iPhone (Safari), Android (Chrome), and everything in between. The layout adapts to small screens, so buttons and inputs stay easy to tap on a 375px-wide display.
Do I need to install anything to use the length converter?
No. The length converter works directly in your web browser — no downloads, no extensions, no signup. Just open the page, use the tool, and get your result instantly. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.