Unit Converter
Convert length, weight, temperature, data sizes, volume, time, and speed instantly. Runs in your browser with exact standard factors — no sign-up, nothing stored.
Category
Conversions run instantly in your browser using exact standard factors. Nothing you enter is sent or stored.
How the converter works
Pick a category, choose your from and to units, and type a number. The result updates as you type, calculated on your device with the exact conversion factors defined by international standards — 1 inch is exactly 25.4 millimeters, 1 pound is exactly 0.45359237 kilograms. Nothing you enter leaves your browser.
Why converters disagree sometimes
If two conversion sites give you slightly different answers, one of them is rounding early. Cheap converters store factors with a few decimal places and compound the error when chaining conversions. We convert through the base unit with full-precision factors and round only the displayed result.
The other classic source of confusion is ambiguous units. A US gallon is not an imperial gallon. A gigabyte is not a gibibyte, even though your operating system may mix them up. Where a unit has variants, we label the one we use.
The categories that matter most
Length and weight cover most everyday needs — recipes, shipping, travel. Temperature handles the Celsius-Fahrenheit divide. Data sizes settle the classic argument about why a 1 TB drive shows up as 931 GB. Volume covers cooking across metric and US kitchens, and speed translates between km/h, mph, and knots.
Frequently asked questions
Are the conversion factors exact?
For unit definitions, yes — most modern units are defined exactly in terms of each other (1 inch = 25.4 mm by definition since 1959). The displayed result is rounded to 10 significant digits, which is more precision than any practical use needs.
Why does my 1 TB drive show only 931 GB?
Drive makers count in decimal gigabytes (1 GB = 1,000,000,000 bytes), while Windows historically counts in binary gibibytes (1 GiB = 1,073,741,824 bytes) and labels them GB. Both are "right." Our Data category converts between the two so you can see exactly where the missing space went.
Is anything I type stored or sent anywhere?
No. The math runs entirely in your browser. There is no server processing, no account, and no log of what you convert.