Converter hub
Weight Converter
Weight and mass conversions link the SI kilogram with the pound, the ounce and the stone. The international avoirdupois pound is exactly 0.45359237 kilograms. Pick a pair below or open the page for the exact factor, a worked example and a full chart.
Units in this category
Weight and mass conversions link the SI kilogram with the pound, the ounce and the stone. The international avoirdupois pound is exactly 0.45359237 kilograms.
| Unit | Symbol | Definition |
|---|---|---|
| Kilograms | kg | The kilogram is the SI base unit of mass; since 2019 it is defined by the Planck constant. |
| Grams | g | The gram is one thousandth of a kilogram and is common in cooking and chemistry. |
| Milligrams | mg | The milligram is one thousandth of a gram and is standard for dosages and trace measurements. |
| Metric Tons | t | The metric ton is exactly 1,000 kilograms and is used for freight and bulk materials. |
| Pounds | lb | The international avoirdupois pound is exactly 0.45359237 kilograms. |
| Ounces | oz | The avoirdupois ounce is one sixteenth of a pound, about 28.35 grams. |
| Stones | st | The stone is 14 pounds, used mainly in the UK and Ireland for body weight. |
All weight conversions
Every listed pair has its own page with the formula, examples and a chart. Choose the starting unit:
Milligrams (mg)
Metric Tons (t)
Stones (st)
Frequently asked questions
How many weight units are supported?
7 units, which gives 14 one-way conversions.
Are the factors exact?
They follow SI and international definitions. Where a unit is approximate by nature (for example Mach, months or fuel economy), the page says so.
Can I convert in both directions?
Yes. Every pair page has a swap link and the calculator accepts any decimal value.