Certified tool
Weight and Mass Converter
Convert kilograms, pounds, ounces, and tons using the avoirdupois definitions.
Exact defined conversion
0.453592 kg
1 lb → Kilogram
Cross-system conversion: US customary → SI / metric. Factors are not silently aliased.
Systems: us-customary → si.
Assumptions
- The avoirdupois pound is exactly 0.45359237 kg.
- Ounce means avoirdupois ounce (1/16 lb), not fluid ounce and not troy ounce.
- Short ton is 2000 lb. Long ton is 2240 lb. Tonne is 1000 kg.
Examples
- 1 pound = 0.45359237 kilograms (exact).
- 16 avoirdupois ounces = 1 pound.
- 1 kilogram = 1000 grams.
How to use
- Enter a non-negative mass.
- Choose avoirdupois or SI units. Labels distinguish short ton, long ton, and tonne.
- Swap to reverse the pair. Copy to place the rounded value on the clipboard.
Limitations
- This converts mass. Everyday “weight” language is accepted, but the factors are mass factors.
- Troy and apothecaries ounces are not included.
- Bathroom-scale force at a local g is not modeled.
FAQ
- Is this ounces of volume or ounces of mass?
- Mass. For liquid volume use the volume or cooking converters and the fluid-ounce units labeled US or Imperial.
- Why is stone grouped with avoirdupois?
- A stone is defined as 14 avoirdupois pounds. It is labeled, not treated as a metric unit.