Unit Converter
A unit converter translates a measurement from one unit to another — kilometres to miles, kilograms to pounds, Celsius to Fahrenheit. FreeToolsKit's converter covers eight everyday categories and shows the exact formula behind every result, so you can check the maths yourself. Conversions are instant and run entirely in your browser.
Last updated: October 20, 2026
1 km = 0.62137119 mi — so 10 km = 6.2137119 mi
Key takeaways
- Eight categories are covered: Length, Weight, Temperature, Volume, Speed, Data, Time and Area.
- Every result shows its working — the formula line states exactly how the number was converted.
- Temperature uses the correct offset formulas (°F = °C × 9/5 + 32); all other categories convert through exact base-unit factors.
- The swap button reverses a conversion in one click, and results update as you type.
How do you convert units with this tool?
- Choose a category such as Weight or Temperature from the tabs.
- Type the value you want to convert in the input box.
- Select the “from” and “to” units — the result appears instantly.
- Read the formula line to see exactly how the result was calculated.
- Press Swap to reverse the direction without re-typing anything.
What is the Unit Converter used for?
- Converting a recipe between grams and ounces or cups and millilitres.
- Checking a speed limit in mph against a dashboard that reads km/h while travelling.
- Turning body weight in stones and pounds into kilograms for a form.
- Working out file sizes between MB, GB and MiB for storage planning.
- Converting room dimensions between square feet and square metres when moving home.
Frequently asked questions
How accurate are the conversions?
Conversions use the exact international definitions — for example 1 inch is exactly 25.4 mm and 1 pound is exactly 0.45359237 kg. Results are rounded for readability, with more precision kept than everyday use needs.
Why does temperature convert differently?
Temperature scales have different zero points, so they need an offset as well as a multiplier: °F = °C × 9/5 + 32. All other categories here are simple ratios, so they convert through a shared base unit.
What is the difference between MB and MiB?
A megabyte (MB) is 1,000,000 bytes, while a mebibyte (MiB) is 1,048,576 bytes (1024 × 1024). Operating systems often report MiB while storage is sold in MB, which is why a drive can look smaller than its box suggests.
Can I convert between categories, like kilograms to litres?
No — units from different categories measure different things. Kilograms measure mass and litres measure volume; converting between them needs the density of a specific substance, which this general converter does not assume.
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