Common conversions tasks
Convert common US customary and metric lengths.
Open calculator Temperature ConverterApply the correct scale and offset for temperature.
Open calculator Cooking Unit ConverterTranslate kitchen quantities while respecting volume and mass differences.
Open calculator Data Storage ConverterCompare decimal storage units and binary quantities.
Open calculatorHow to use these calculators
A conversion preserves a quantity while changing its unit. Length can convert to length and mass to mass, but one physical dimension cannot become another without extra information. Choose the source unit that describes the entered number and the target unit required by the recipe, drawing or specification.
Most units use a multiplication factor through a base unit. Temperature scales also use an offset, so a simple ratio is not enough. Digital storage may use decimal prefixes or binary units, and apparel sizing is a convention rather than a physical equivalence. The guide attached to each reviewed converter explains which definition or table the engine uses.
Three checks that change the answer
Match the dimension
Volume and mass require density to convert between them; a cup of one ingredient does not weigh the same as a cup of another.
Distinguish exact and approximate
Defined unit relationships can be exact while measured inputs and size charts remain approximate.
Read the unit symbol
Case and prefixes matter: millimeters, meters and megameters represent very different scales.
Before you use the answer
- Confirm source and target describe the same kind of quantity.
- Keep the original measurement precision.
- Check decimal versus binary storage conventions.
- Use a product-specific chart for apparel sizes.
Browse all 14 conversions calculators
Every tool calculates in your browser. Pages marked “Reviewed guide” also include topic-specific explanations and source checks.
- Roman Numeral ConverterReviewed guideConvert standard Roman numerals and decimal integers from 1 through 3,999.
- Length ConverterReviewed guideConvert common metric and US customary length units.
- Weight ConverterReviewed guideConvert kilograms to pounds and ounces, and between grams, ounces, pounds, stones and US and metric tons.
- Shoe Size ConverterReviewed guideEstimate adult EU, UK and US shoe sizes from one size or foot length.
- Temperature ConverterReviewed guideConvert temperatures among Celsius, Fahrenheit and kelvin while enforcing the physical absolute-zero boundary.
- Conversion CalculatorReviewed guideConvert common length, mass, area, volume and temperature units with dimensional validation.
- Cooking Unit ConverterReviewed guideConvert ounces to cups and every common US kitchen volume, from teaspoons to gallons and milliliters.
- Pressure ConverterReviewed guideConvert pressure among SI and common engineering units.
- Torque ConverterReviewed guideConvert torque among newton-meters, pound-feet, pound-inches and kilogram-force meters.
- Energy ConverterReviewed guideConvert energy among joules, watt-hours, BTU and dietary kilocalories.
- Power ConverterReviewed guideConvert power among watts, kilowatts, horsepower and BTU per hour.
- Data Storage ConverterReviewed guideConvert decimal storage units and IEC binary storage units without mixing their definitions.
- Angle ConverterReviewed guideConvert angular measure among degrees, radians, gradians, turns and arcminutes.
- Speed Unit ConverterReviewed guideConvert speed among metric, US customary and nautical units.
Frequently asked questions
Why can a converted value have many decimals?
The exact factor may produce a repeating decimal, while the input itself may justify fewer digits.
Can cups convert directly to grams?
Only with the ingredient's density or a tested ingredient-specific reference.
Why are clothing sizes approximate?
Brands and regions use sizing conventions and fit allowances rather than one universal physical definition.
Are GB and GiB the same?
No. GB normally uses powers of 1000, while GiB uses powers of 1024.
Reference starting points
Individual reviewed guides cite the equation or standard used by that calculator. These authorities provide broader context for this collection.