Unit converter

Convert length, weight, volume, temperature, speed, data and more instantly in your browser. Both fields are editable, nothing is uploaded.

How to convert units

1
Choose the unit category
Pick from length, mass, volume, temperature, area, speed, time, digital storage, pressure, energy, power, angle, frequency or fuel economy.
2
Type a value in either field
Both the source and result fields are editable. Change either one and the other updates immediately, so you can work in whichever direction is convenient.
3
Copy the result or the full table
A table of common values around your input is built automatically, and can be downloaded as a CSV for reference or for pasting into a spreadsheet.

Why KB and KiB are not the same size

Storage manufacturers and network speeds count in decimal kilobytes, where 1 KB is exactly 1,000 bytes, the same pattern as a kilometer being 1,000 meters. Operating systems and file managers historically counted in binary instead, where 1 KiB is 1,024 bytes, because computers work in powers of two internally. The two units differ by about 2.4% at the kilo scale and by 20% once you reach terabytes, which is exactly why a drive labelled "1 TB" shows up as roughly 931 GiB in your file manager. This tool keeps the two families strictly separate rather than quietly picking one.

Why temperature does not convert like other units

Length, mass and most other quantities convert with a simple multiplier: double the meters, double the feet. Temperature scales instead have different zero points (0°C is not the same physical temperature as 0°F), so converting a single reading needs both a multiplication and an offset (F = C × 9/5 + 32). That offset only applies to a single point on the scale, not to a difference between two temperatures: a 10°C rise is an 18°F rise, not a 50°F one, because the offset cancels out of the subtraction. This tool flags that distinction directly on the temperature page.

Every conversion happens in your browser

The value you type, the units you pick and the result are never sent to a server; the whole calculation runs locally in JavaScript. The page works fully offline once loaded, and a shareable link only ever encodes your chosen units and value, never anything else.

Frequently asked questions

Why are KB and KiB shown as different units?

KB (kilobyte) is 1,000 bytes, following the same decimal pattern as every other metric unit. KiB (kibibyte) is 1,024 bytes, the binary unit your operating system often uses instead. This tool keeps them as separate options so a conversion between the two is exact rather than assumed.

Why are the US and imperial gallon different?

They were standardised independently: the US liquid gallon is about 3.785 liters, while the imperial gallon used in the UK and historically in Canada is about 4.546 liters, roughly 20% larger. Always check which one a recipe, fuel figure or tank capacity is quoting before converting.

How do I convert a temperature difference, not a reading?

Multiply the difference by the scale ratio only, without adding the 32° offset: a change of 10°C equals a change of 18°F (10 × 9/5), not 50°F. This tool's temperature page converts single readings correctly by default; differences need the ratio-only version described here.

How many decimal places does the result show?

Six by default, adjustable from 0 to 10. Results far outside a normal range switch automatically to scientific notation so very small or very large numbers stay readable.

Can I share a link with my exact conversion?

Yes. The unit category, both units and the value you entered are all reflected in the page's settings, so bookmarking or sharing the page reproduces the same calculation.

Where do the conversion factors come from?

From convert-units, a widely used open-source conversion library, for the twelve standard categories. Digital storage and fuel economy are calculated directly from their defining formulas, since those two need a decimal/binary distinction and a formula-based relationship that a general-purpose library does not provide.

Does this tool work offline?

Yes, once the page has loaded in your browser. Every conversion is plain arithmetic running locally; there is no server round-trip for any calculation, so a lost connection does not interrupt anything.