Mass/Weight Converter
Convert mass measurements between metric and customary units.
Converter guide
About Mass and Weight Converter
This converter changes mass values between metric and customary units such as grams, kilograms, tonnes, ounces, pounds, stone, and short tons. Everyday speech often calls mass weight, but physics distinguishes mass from the force of gravity acting on it.
How to use this converter
- 1Enter the value and choose its source unit. Check whether a ton means a metric tonne or a US short ton.
- 2Select the destination unit and review the converted number with its label.
- 3For engineering or science work, use mass units in equations unless the formula specifically asks for weight as a force.
Conversion method and technical details
The converter uses kilograms as a common base and applies fixed factors for each supported unit. For example, one international pound is exactly 0.45359237 kg, while a metric tonne is 1,000 kg. The factors describe mass, not gravitational force.
Worked real-world example
A 10 lb mass is about 4.5359 kg. On Earth its weight force is about 44.5 N, which is a different quantity from the mass conversion.
Common scenarios and use cases
Translate package weights, cooking quantities, body-mass measurements, and technical data across unit systems.
For a dependable comparison, confirm both unit labels, keep the original measurement with the converted value, and use the precision required by the task. The converter changes the representation of a value; it does not measure the item or decide which standard your project requires.
Important details and limitations
The tool does not measure an object and cannot resolve differences in historical or trade definitions unless a unit is specifically listed. For shipping, follow the carrier's rules and the scale's calibration.
Check the output unit as well as the number. If the result will be reused in another calculation, retain full precision where possible and round only at the end. For measurements governed by a technical specification, use the standard and tolerance required by that document.
Frequently asked questions
Are mass and weight the same?
In daily use the words overlap, but mass is measured in kilograms and weight is a force measured in newtons.
What is a short ton?
It is a US customary unit equal to 2,000 pounds, distinct from a 1,000 kg metric tonne.
Why do I need to know which ton?
The unit names refer to different amounts, so choosing the wrong type changes the result substantially.
Why can the converted number look much larger or smaller?
Different units use different scales. A measurement can have a larger number in a smaller unit and still describe the same quantity. Check the source and target unit labels before comparing values.
How many decimal places should I keep?
Keep enough precision for the job and avoid rounding values between steps. Round the final displayed answer to match the specification, document, or measuring tool you are using.