Type a conversion
Type it the way you would say it, such as 5 ft 11 in to cm or 30 psi in bar, and press Enter. Or pick a category from the list and choose the two units.
ConvertAllFree Conversion Calculator for Units, Kitchen Measures and Sizes
Convert over 370 units in 33 categories by typing them the way you say them, see both scales on a tape and every unit at once, and work out cups to grams, oven heat, clothing, shoe and ring sizes, tyres, time zones, BMI, bigha and lakh and crore, with nothing uploaded.
Saved and recent
Unit pairs you saved with the star, and the conversions you made recently. Both stay on this device.
Saved pairs
Recent conversions
Settings
Changes apply at once and are kept in this browser on this device.
Numbers
Also sets how typed numbers are read, so 1,5 means one and a half only with a comma format.
Your data
Privacy
- Every conversion is worked out in this browser: what you type is not sent anywhere.
- Saved pairs, recent conversions, tool values and settings are kept in this browser on this device, and only after you change something. The browser's storage is not encrypted, and clearing this site's data deletes them.
- Reset everything removes them at once.
Nothing you type leaves this browser. Press / to type a conversion, Alt+S to swap units.
How to Use ConvertAll
Change either side
Type in the From box or the To box; the other one follows. Fractions, sums and mixed units such as 5 ft 11 in work in both, and the swap button turns the units round.
Drag the tape
The yellow tape shows your value on both scales at once. Drag it, or use the arrow keys, to see the values around it, and zoom with plus and minus.
See every unit
Under the tape, the value appears in every unit of the category. Filter the list, pin the units you use most to the top, and copy any value.
Save the pairs you use
Save pair keeps a conversion in the quick pairs row, and recent conversions appear under Saved, so the ones you need are a click away.
Use the practical tools
Cooking and recipe scaling, oven heat, clothing, shoe and ring sizes, trip fuel cost, tyres, time zones, number bases, paper sizes, wire gauges, BMI and lakh and crore.
Why Use This Conversion Calculator?
🗣️ Type it as you say it
No menus to search through first: a line such as 2 m + 30 cm in ft finds the category, reads the sum and converts it, and a note shows how it was read.
✅ Exact when it can be
Factors come from the published definitions, and each answer says whether it is exact, rounded or approximate, with the formula beside it.
🇮🇳 Indian units included
Tola, seer, maund, bigha, guntha, cent, marla, kanal and katha sit beside metric and US units, and amounts turn into lakh and crore and words for a cheque.
🍳 Real kitchen weights
A cup of flour and a cup of sugar weigh very different amounts. The cooking tool uses the USDA's cup weights, and the recipe scaler rounds to kitchen fractions.
🔢 Your number format
Choose 1,234.5, 12,34,567.89, 1.234,5 or 1 234,5, the precision and scientific notation; typed numbers are read the same way.
🔒 Nothing uploaded
There is no account and no upload. Conversions are worked out on your device, and saved pairs stay only in this browser.
Units and Conversions Explained
📐 Where the sizes come from
Most units are fixed by definition. Since 1959 an inch is exactly 2.54 cm and a pound exactly 0.45359237 kg, and the US gallon is 231 cubic inches. A litre is a cubic decimetre. So most conversions are a simple multiplication, and the factor can be written out in full.
🌡️ When it is not a multiplication
Temperature scales start at different zeros, so 0 °C is 32 °F and the formula adds as well as multiplies. Fuel economy turns upside down between kilometres per litre and litres per 100 km: twice the distance per litre means half the litres per 100 km. ConvertAll shows each formula.
🗺️ Units that vary by place
Some units carry one name for several sizes. A US gallon is 3.785 litres and a UK gallon 4.546; a bigha can be 27,225 sq ft in one district and 14,400 in another. ConvertAll keeps them apart and marks the regional ones as approximate.
Frequently Asked Questions
How do I type a conversion?
Type it the way you would say it, in the search bar above the converter: "5 ft 11 in to cm", "72 f to c", "3 bigha in acres" or "500 GB to GiB", then press Enter. The two number boxes understand more than plain numbers too: fractions such as 1 1/2, sums such as 2 m + 30 cm, and powers such as 2.5e3. A note under the box shows how your text was read.
What do Exact, Rounded and Approximate mean?
Exact means the answer shown is complete to its last digit, because the two units are related by a short decimal (a mile is exactly 1.609344 km). Rounded means more digits exist; raise the precision in Settings to see them. Approximate means one of the units has no single fixed size, such as a regional land measure like the bigha, or an em, whose size depends on the text.
Where do the conversion factors come from?
From the published definitions: NIST Special Publication 811 and NIST Handbook 44 for US and imperial units (on the international foot, since the US survey foot was retired at the end of 2022), the SI Brochure for metric units, CODATA 2022 for the dalton and the charge of an electron, the CSS standard for screen units (96 pixels to the inch), NIST's binary prefixes for KiB and MiB, and the Standards of Weights and Measures Act, 1976 for the tola, seer and maund.
Why do bigha, katha and other land units say Approximate?
Traditional Indian land measures differ from state to state and even between districts: a bigha can be 14,400, 17,424 or 27,225 square feet, among others. ConvertAll names the size each one uses (for example "Bigha, 27,225 sq ft"), so you can pick the one your area uses. Check the size in your own land records, or ask the local revenue office, before you rely on it for a sale or a document.
Is anything I type sent or saved?
Nothing you type is sent anywhere: every conversion is worked out in your browser. Saved pairs, recent conversions, tool values and settings are kept in this browser on this device, and only after you make a change. Reset everything in Settings removes them.
Where do the kitchen, oven and BMI figures come from?
Cup weights of ingredients are the U.S. Department of Agriculture's (FoodData Central), and you can type your own. Gas marks and fan oven settings follow the oven chart of Which?, the UK consumer body. BMI uses the WHO cut-offs (18.5, 25 and 30) or, for India, the India Obesity Commission's 2025 cut-offs (normal up to 22.9). The clothing, shoe and ring charts are examples, because brands size differently.
What happened to UnitSwap, and how does ConvertAll differ from the site's other converters?
UnitSwap, the site's earlier unit converter, became part of ConvertAll on 15 November 2026, so the site has one unit converter instead of two, and UnitSwap's old address opens this page. Its units are all here: 24 were added for that, among them three old temperature scales, the rood, the barn and boiler horsepower. Only Mach, the jiffy and the computer word sizes were left out, because they have no single fixed size. ConvertAll covers 33 categories with over 370 units, reads conversions typed in words, shows a two-scale tape and adds kitchen, size, travel, Indian and science tools. A few of its tools are also tools of their own on this site: BaseShift converts number bases, the Time Zone Converter compares cities, AutoCalc compares tyre sizes and trip costs in more detail, HomeCalc measures property areas with land units, EngCalc sizes cables, and Passport Photo Maker makes passport photos. Use whichever fits the job.