How to Use
Convert between units instantly:
- Select a category from the pill buttons at the top (Length, Weight, Temperature, etc.).
- Enter a value in the From field. The result updates instantly as you type.
- Use the dropdowns to change the From and To units.
- Click the swap button to flip the From and To units along with their values.
- Use the Popular conversions shortcuts at the bottom to quickly jump to common conversions.
Categories
- Length — Millimeter, Centimeter, Meter, Kilometer, Inch, Foot, Yard, Mile, Nautical Mile, Micrometer
- Weight — Milligram, Gram, Kilogram, Metric Ton, Ounce, Pound, Stone, US Ton
- Temperature — Celsius, Fahrenheit, Kelvin
- Volume — Milliliter, Liter, US Gallon, Quart, Pint, Cup, Fluid Ounce, Tablespoon, Teaspoon, Cubic Meter, Cubic Foot
- Area — Sq mm, Sq cm, Sq m, Sq km, Sq in, Sq ft, Sq yd, Sq mi, Acre, Hectare
- Speed — m/s, km/h, mph, Knot, ft/s, Mach
- Time — Millisecond, Second, Minute, Hour, Day, Week, Month, Year
- Data — Bit, Byte, KB, MB, GB, TB, PB, KiB, MiB, GiB
- Energy — Joule, Kilojoule, Calorie, Kilocalorie, Watt-hour, Kilowatt-hour, BTU, Electronvolt
- Pressure — Pascal, Kilopascal, Bar, Atmosphere, PSI, mmHg
Tips
- Results update in real time as you type — no need to click a convert button.
- The formula line below the converter shows the conversion rate for reference.
- Use the swap button to quickly reverse a conversion.
- Popular conversions at the bottom let you jump to common unit pairs with one click.
- Data category includes both decimal (KB, MB, GB) and binary (KiB, MiB, GiB) units.
Frequently Asked Questions
How many unit categories are available?
There are 10 categories: Length, Weight, Temperature, Volume, Area, Speed, Time, Data, Energy, and Pressure — covering over 80 individual units in total.
How are temperature conversions handled?
Temperature conversions use exact formulas (not simple multiplication) to convert between Celsius, Fahrenheit, and Kelvin for perfect accuracy.
What is the difference between KB and KiB?
KB (kilobyte) uses the decimal definition where 1 KB = 1,000 bytes. KiB (kibibyte) uses the binary definition where 1 KiB = 1,024 bytes. The Data category includes both decimal and binary units.
Does the converter work offline?
Yes. All conversions are calculated locally in your browser using built-in conversion factors. No internet connection is needed after the page loads.
Where can I see the conversion formula?
The formula line displayed below the converter shows the conversion rate between your selected units for reference.
About
Unit conversion is one of the most common everyday calculations, whether you're cooking, traveling, studying, or working on a project. This tool covers 10 categories with over 80 units to handle virtually any conversion you need.
All conversions are calculated locally in your browser using precise conversion factors. No data is sent to any server. Temperature conversions use exact formulas rather than multiplication factors for perfect accuracy.
From the build: every unit in a category is stored as a single conversion factor to a chosen base unit — meters for length, grams for weight, pascals for pressure. To convert A to B you go through the base, which means N units only need N factors instead of N×N pairs. Temperature breaks this pattern because Celsius and Fahrenheit aren't proportional — they have an offset — so that category uses explicit formulas instead. The data category was the only place we had to be careful about names: 1 KB is 1,000 bytes and 1 KiB is 1,024, and mixing them up silently is exactly the kind of bug we wanted to keep out.