Unit Converter — How to Use It Online for Free
The Unit Converter converts length, weight, temperature, area, volume, speed and data sizes between metric and imperial units — km to miles, kg to pounds, °C to °F, sq ft to sq m and more — instantly, in both directions.
Conversions go wrong in predictable ways: recipes in cups and Fahrenheit, a treadmill in miles, land measured in square feet while your notes are in metres. The formula shown with each result matters — it lets you sanity-check the answer and reuse the same conversion on paper later. Data sizes (KB, MB, GB) follow the convention computers use, so file sizes convert the way your device reports them.
How to use the Unit Converter
- Choose the category — Length, Weight, Temperature, Area, Volume, Speed or Data.
- Type the value and pick the 'from' and 'to' units.
- Read the result and the formula used.
- Use Swap to reverse the conversion instantly.
A worked example
A flat is listed as 1,150 sq ft and you think in square metres. Choose Area, enter 1150 sq ft → about 106.8 sq m. Now you can compare it fairly with the other flat listed in metres.
Tips for better results
- Swap is the fastest way to check a conversion — convert back and you should land on your starting number.
- For cooking, remember the converter handles temperature: 180°C is 356°F for ovens marked in Fahrenheit.
- Height in feet and inches: convert your centimetres once and remember the result — forms ask often.
A note on online calculators
Online calculators are only as good as the numbers typed into them, so two habits matter. First, decide what the result should roughly be before you calculate — an expected range catches the classic errors, like a misplaced decimal or a rate entered per month instead of per year. Second, read the labels: many money mistakes are really direction mistakes (adding tax instead of removing it, dividing by the new value instead of the original). The calculators here show the full picture — not just the headline figure but the totals and splits behind it — so you can see whether the answer makes sense, and adjust the inputs until it does.
Common questions
Why is temperature conversion different from the others? Most units scale by simple multiplication, but temperature scales start at different zero points — so °C to °F needs the ×9/5 and +32 you see in the formula. It is the one conversion you cannot do with a single multiplier.
Which units does India use day to day? Mostly metric — km, kg, litres — but real life mixes in feet and inches for height and rooms, square feet for flats, and Fahrenheit on some weather reports and ovens. This converter covers both worlds.
Do I need to sign up or install anything? No. The Unit Converter is completely free, needs no account and nothing to install — it runs in your browser, and anything you type stays on your device.
One tool rarely finishes the whole job. The natural companions to this one are covered in the Age Calculator guide and the Color Picker guide — between them, most calculation tasks can be handled end to end in the browser, with no installs and no accounts.