Weight (technically mass) conversion trips people up whenever a recipe, shipping label, or fitness app uses a different unit system than the one you're used to. This converter handles six common weight units using grams as the internal reference point.
Conversion factors used
| Unit | Grams equivalent |
|---|---|
| 1 milligram (mg) | 0.001 g |
| 1 kilogram (kg) | 1,000 g |
| 1 ounce (oz) | 28.3495 g |
| 1 pound (lb) | 453.592 g |
| 1 stone (st) | 6,350.29 g |
Worked examples
| From | To | Result |
|---|---|---|
| 1 kg | pounds | 2.20 lb |
| 16 oz | grams | 453.6 g |
| 10 st | kg | 63.5 kg |
See our metric vs. imperial conversion guide for exact formulas across length, weight, and temperature.
Common mistakes
- Confusing weight with mass. In everyday use these terms are used interchangeably, though technically weight is a force and mass is the underlying quantity — this distinction rarely matters for practical conversions on Earth.
- Mixing up stone and pounds. One stone equals 14 pounds, a unit mainly used in the UK and Ireland for body weight.
A real-world mix-up
Airline baggage allowances are a common place this trips people up: a US traveler used to seeing weight limits in pounds may book a flight from an airport that lists the limit in kilograms, and a "23 kg" allowance (about 50.7 lb) can look deceptively small if misread as 23 lb. The mistake usually surfaces at check-in, when an overweight bag triggers an unexpected fee — checking the unit on your ticket or airline website before packing avoids the surprise.
References
- National Institute of Standards and Technology (NIST) — official unit definitions
Frequently asked questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds.
How many pounds are in a stone?
One stone equals exactly 14 pounds, a unit commonly used in the UK and Ireland.
How do I convert ounces to grams?
Multiply the number of ounces by approximately 28.3495 to get grams.
Why do airlines list baggage weight limits in kilograms?
Most of the world's aviation industry operates on the metric system for standardization across international routes, so kilograms are the default even on flights departing from countries that use pounds elsewhere.