All converters
Showing 1 of 1 converter
Unit Converter
Convert between metric and imperial units across eight categories, instantly.
Open toolThe free unit converter covers eight categories - length, weight, temperature, volume, area, speed, data and time - with metric and imperial units in each. Pick a category, choose your two units, and the result appears as you type.
Conversions run through a base unit for each category rather than a table of hard-coded pairs, so any unit converts directly to any other in the same category without stacking rounding errors along the way.
What the free unit converter handles
- Length: millimetres, centimetres, metres, kilometres, inches, feet, yards, miles and nautical miles.
- Weight: milligrams, grams, kilograms, tonnes, ounces and pounds.
- Temperature: Celsius, Fahrenheit and Kelvin.
- Volume, area, speed, data and time, each with their own metric and imperial units.
Why temperature works differently
Most conversions are pure multiplication, because zero means the same thing in both units - zero metres is zero feet, zero kilograms is zero pounds.
Temperature scales do not share a zero point. Zero Celsius is the freezing point of water, zero Fahrenheit is something else entirely, and zero Kelvin is absolute zero. Converting between them requires shifting the scale as well as stretching it, which is why 0 °C comes out as 32 °F rather than 0 °F.
Frequently asked questions
Is the unit converter free?
Yes, free with no sign-up. It runs entirely in your browser and keeps working without a connection once the page has loaded.
Which categories are supported?
Eight: length, weight, temperature, volume, area, speed, data and time, each with metric and imperial units.
How do I convert Celsius to Fahrenheit?
Multiply by 9, divide by 5, then add 32 - so 20 °C is 68 °F. Choose the temperature category in the converter and it does it for you.
Can I convert between any two units?
Any two units within the same category, yes. Conversions go via a base unit, so every unit connects to every other one.
Other free tools on VSThiran
Free online calculators
Percentages, BMI, age, discounts, tips, loans, EMI and compound interest.
Free scientific calculator
Type whole expressions with brackets, trigonometry, logarithms and powers.
Free PDF tools
Merge, split and convert PDF files without uploading them anywhere.
Free business document tools
Invoices, quotations and receipts as downloadable A4 PDFs.