Weight conversions
Weight (mass) covers kilograms, grams, pounds, ounces, stone, and related units for luggage, cooking, shipping, and body weight. Convert with exact factors and keep one home unit for logs and forms.
Tip: convert through kilograms when mixing metric and customary weight. Stone is 14 pounds—do not paste decimal stone into a kilogram form. Kitchen ounces are avoirdupois, not troy.
Popular Weight conversions
All Weight units
Select any unit to open the converter. You can change the target unit on the next screen.
How our Weight converter works
Every conversion goes through a carefully defined base unit for Weight. We use arbitrary-precision decimal arithmetic so results stay stable for scientific work, homework, and professional estimates alike.
Open a conversion pair for formulas, a reference table, worked examples, and short FAQs tailored to those two units.
Common conversions
- Centimetre to Inch (International)
- Inch (International) to Centimetre
- Inch (International) to Foot (International)
- Millimetre to Inch (International)
- Inch (International) to Millimetre
- Meter to Foot (International)
- Foot (International) to Meter
- Kilometre to Mile (International)
- Mile (International) to Kilometre
- Centimetre to Foot (International)
- Foot (International) to Centimetre
- Meter to Yard (International)
- Yard (International) to Meter
- Meter to Kilometre
- Foot (International) to Inch (International)
- Yard (International) to Foot (International)
- Nanometre to Meter
- Light Year to Kilometre
- Celsius to Fahrenheit
- Fahrenheit to Celsius
- Celsius to Kelvin
- Kelvin to Celsius
- Fahrenheit to Kelvin
- Kelvin to Fahrenheit
- Square Metre to Square Foot
- Square Foot to Square Metre
- Acre to Hectare
- Hectare to Acre
- Square Kilometre to Square Mile
- Square Mile to Square Kilometre
- Square Inch to Square Centimetre
- Square Centimetre to Square Inch
- Square Metre to Hectare
- Acre to Square Metre
- Litre to Cubic Metre
- Cubic Metre to Litre
- Millimetre to Litre
- Litre to Millimetre
- Cup to Millimetre
- Millimetre to Cup
- Cubic Foot to Litre
- Litre to Cubic Foot
- Tablespoon (Metric) to Teaspoon (Metric)
- Teaspoon (Metric) to Tablespoon (Metric)
- Hectolitre to Litre
- Litre to Hectolitre
- Kilogram to Pound (Avoirdupois)
- Pound (Avoirdupois) to Kilogram
- Gram to Ounce (Avoirdupois)
- Ounce (Avoirdupois) to Gram
- Kilogram to Stone
- Stone to Kilogram
- Tonne (Metric) to Pound (Avoirdupois)
- Pound (Avoirdupois) to Tonne (Metric)
- Gram to Kilogram
- Kilogram to Gram
- Milligram to Gram
- Gram to Milligram
- Kilometre per hour to Mile per hour
- Mile per hour to Kilometre per hour
- Metre per second to Kilometre per hour
- Kilometre per hour to Metre per second
- Mile per hour to Foot per second
- Foot per second to Mile per hour
- Knot to Kilometre per hour
- Kilometre per hour to Knot
- Metre per second to Mile per hour
- Mile per hour to Metre per second
- Minute to Second
- Second to Minute
- Hour to Minute
- Minute to Hour
- Day to Hour
- Hour to Day
- Week to Day
- Day to Week
- Year (Julian) to Day
- Day to Year (Julian)
- Hour to Second
- Second to Hour
Precision Unit Converter: Metric, Imperial & Scientific
Quickly convert between hundreds of units across Length, Temperature, Area, and Volume. Whether you are a student, engineer, or hobbyist, our tool provides high-precision results for everything from everyday measurements to advanced scientific data.
Comprehensive Categories
- Length: Nanometres to Light Years and Planck Length.
- Temperature: Celsius, Fahrenheit, Kelvin, and Newton.
- Area: Square Meters, Acres, Hectares, and Barns.
- Volume: Litres, Cubic Inches, Gallons, and Millilitres.
Why Use Our Converter?
- Ultimate Precision: Powered by Decimal.js for zero rounding errors.
- Scientific Grade: Includes rare units like Bohr, Ångström, and Parsecs.
- Instant Results: Real-time conversion as you type.
- Mobile Friendly: Optimized for use on any device.
Our free online converter is the fastest way to switch between metric and imperial systems. Save time on complex math and get reliable conversions for school, lab work, or construction projects.