You read a recipe in pounds and ounces and cook in kilos and grams. An article mentions the temperature in Fahrenheit and you need to know what that is in Celsius. A hard drive is advertised in GB but your operating system shows it in GiB, and the number doesn't add up. Each of these conversions is simple on its own, but bundling every category into one tool saves you from having to look up a different calculator for each unit type.
The categories a complete unit converter covers
- Length: meters, feet, miles, inches, and the rest of the metric and imperial system units.
- Weight: kilograms, pounds, ounces, tons.
- Temperature: Celsius, Fahrenheit, Kelvin, each with its own non-linear conversion formula relative to the others.
- Area: square meters, hectares, acres, square feet.
- Volume: liters, gallons, milliliters, fluid ounces.
- Speed: km/h, mph, knots, m/s.
- Digital storage: bytes, KB, MB, GB, TB, with the important distinction between decimal (base 1000) and binary (base 1024) units.
- Time: seconds, minutes, hours, days, and conversions between them.
- Pressure: pascals, bar, PSI, atmospheres.
How to convert between units
- Choose the corresponding category (length, weight, temperature, etc.).
- Enter the value in the source unit.
- Choose the destination unit and get the result instantly.
You can do it free with the unit converter on this site, with over 80 units available.
The special case of temperature: why it's not a simple multiplication
Unlike most conversions (which are multiplying by a fixed factor), converting between Celsius, Fahrenheit and Kelvin requires formulas with an offset in addition to a scale factor, because the three scales have different zero points. This is why "adding 32" to Celsius to get Fahrenheit only works as a quick mental approximation, not an exact conversion, unless the correct scale factor is also applied.
The special case of digital storage: decimal vs. binary
A hard drive manufacturer usually advertises capacity in decimal GB (1 GB = 1,000,000,000 bytes), while the operating system often shows it in binary GiB (1 GiB = 1,073,741,824 bytes). This difference (not a manufacturing error) is the usual reason why a "1TB" drive shows up as somewhat less than 1TB in Windows File Explorer.
Frequently asked questions
Why does my hard drive show less capacity than advertised? Because of the difference between decimal units (used in marketing) and binary units (used by the operating system), not a defect in the drive.
Are the temperature conversions exact? Yes, the exact conversion formulas between Celsius, Fahrenheit and Kelvin are applied, not approximations.
How many units does it cover in total? Over 80, spread across the different categories (length, weight, temperature, area, volume, speed, storage, time and pressure).
Is anything I convert saved? No, all the calculation happens in your browser.
Convert between 80+ units for free with the unit converter, covering length, weight, temperature, volume and more.