How Weight Converter Works
Every weight unit is converted through kilograms, the base unit. A pound is defined as exactly 0.453592 kilograms and an ounce as 0.0283495 kilograms, so your input is multiplied by its unit's factor to get a kilogram value, then divided by each other unit's factor to produce the full set of results at once.
How to Use This Tool
- Enter the number you want to convert into the value field.
- Pick the unit that number is currently measured in from the dropdown.
- The results box lists the equivalent in every other supported weight unit, updating live as you type.
- Select Reset to clear everything and start over.
Example
Converting 150 pounds: 150 × 0.453592 = 68.0388 kilograms, which is also 68,038.8 grams and about 10.71 stone (68.0388 ÷ 6.35029).
Helpful Tips
- In the US, body weight is usually given in pounds; in the UK it's often given in stone and pounds combined, while most of the rest of the world uses kilograms.
- Milligrams and grams are most useful for small quantities like ingredients or medication dosages; tonnes are for large industrial or shipping weights.
Frequently Asked Questions
Is this converting weight or mass?
Technically kilograms and grams measure mass while pounds and ounces are traditionally units of force (weight), but in everyday and commercial use they're treated as directly interchangeable, which is how this converter works.
What's a stone, and why is it only used sometimes?
A stone equals 14 pounds (6.35029 kg) and is the everyday unit for body weight in the UK and Ireland. It's rarely used outside those countries, which is why it isn't as globally common as kilograms or pounds.
Is a UK tonne the same as a US ton?
No. This tool uses the metric tonne (1,000 kg), which differs slightly from the US short ton (about 907.18 kg) and the UK long ton (about 1,016.05 kg) — those aren't included here.
How accurate are the pound and ounce conversions?
They use the internationally agreed exact avoirdupois definitions (1 lb = 0.453592 kg, 1 oz = 0.0283495 kg), so results are precise, not rounded estimates.
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