Math Tools
Online Weight and Mass Unit Converter
Convert among mg, g, kg, metric tonnes, oz, lb, and stone with integer-based arithmetic and see every equivalent in one table.
Seven units, one integer base
Convert weight and mass units
Metric tonne and avoirdupois definitions are used.
Converted value
Mass conversion result
Exact definitions are calculated before display rounding.
| Unit | Equivalent value |
|---|
Quick answer
How do I convert kilograms to pounds?
One avoirdupois pound is exactly 0.45359237 kilogram, so divide kilograms by 0.45359237. For example, 1 kilogram is approximately 2.204622622 pounds.
How to use this tool
- Enter a non-negative mass and select its source unit.
- Choose the target unit, swap units, or use a popular example; results update automatically.
- Confirm the unit definition and suitable precision, then export to Print, Excel, PDF, or TXT if needed.
How the calculation works
Integer nanograms are the common base: 1 mg = 1,000,000 ng, 1 g = 1,000,000,000 ng, 1 kg = 1,000,000,000,000 ng, 1 metric tonne = 1,000,000,000,000,000 ng, 1 avoirdupois ounce = 28,349,523,125 ng, 1 avoirdupois pound = 453,592,370,000 ng, and 1 stone = 6,350,293,180,000 ng. Input is scaled by 1,000,000 and calculated with BigInt before half-up rounding to at most 9 decimals.
Examples
| Example | Input | Expected result |
|---|---|---|
| One kilogram | |
2.204622622 lb or 35.27396195 oz |
| One avoirdupois pound | |
exactly 0.45359237 kg and 16 oz |
| One stone | |
exactly 14 lb or 6.35029318 kg |
Limitations
- Inputs must be non-negative, no greater than 999,999,999,999, and have at most 6 decimals. Weight force, newtons, and local-gravity calculations are outside scope.
- Ton means metric tonne only; U.S. short ton and imperial long ton are not supported.
- Pound and ounce mean avoirdupois, not troy, apothecaries, or historical systems.
- Primary results are rounded half up to at most 9 decimals; exact factors do not add accuracy to a real weighing.
- The result is for general conversion, not metrology, trade, medical, or pharmaceutical certification.
Frequently asked questions
Which ton does this tool use?
It uses the metric tonne, symbol t, equal to 1,000 kilograms. It does not use the U.S. short ton or imperial long ton.
Which pound and ounce definitions are used?
The tool uses the avoirdupois pound and ounce for general mass. One pound is 16 ounces. It does not use the troy ounce used for precious metals.
Are weight and mass different?
Yes in physics: mass is measured in kilograms and weight force in newtons. This page keeps common search wording but performs mass-unit conversions only.
Does the website store the value I enter?
No. Conversion and file generation happen in your browser without sending the entered value to the server.
References
- NIST Handbook 133 (2026) Appendix E — mass conversion factors Verified 2026-07-31
- BIPM — SI base unit: kilogram Verified 2026-07-31
- Legacy THcount — weight unit converter Verified 2026-07-31
Content and calculation method last reviewed: