Metric and imperial weight conversions
Weight Converter
Convert milligrams, grams, kilograms, ounces, pounds and US tons instantly with our free online weight converter. Perfect for fitness, cooking and shipping. No signup required.
Convert Weight
Results update as you type.
How to Convert Weight Units
Weight and mass conversions come up constantly in everyday life: tracking gym progress in kilograms or pounds, weighing ingredients for recipes, calculating postage, or comparing product weights between countries. The metric system (milligrams, grams, kilograms) is used for almost all scientific work and most of the world, while pounds and ounces remain the everyday units in the United States and are common in the UK for body weight and cooking.
Key Weight Conversion Formulas
1 kg = 2.20462 lb (the most-asked conversion)
1 lb = 453.592 g, or 0.4536 kg
1 oz = 28.3495 g
1 US ton = 907.185 kg (2,000 lb)
Our calculator expresses every unit relative to the kilogram using exact conversion factors, then converts to the unit you choose. So converting kg to lb is a single multiplication, and the result is accurate to as many decimal places as you need.
Common Weight Conversions
| Unit | Equals | Real-world reference |
|---|---|---|
| 1 kilogram (kg) | 2.2046 lb | A bag of sugar is 1 kg in most of the world |
| 1 pound (lb) | 453.6 g | A standard loaf of bread |
| 1 ounce (oz) | 28.35 g | A slice of cheese is about 1 oz |
| 1 stone (14 lb) | 6.35 kg | Still used for body weight in the UK |
| 1 gram (g) | 0.0353 oz | A paperclip weighs about 1 g |
| 1 US ton | 907.2 kg | 2,000 pounds |
Practical Uses for a Weight Converter
- Fitness and health: Gym plates are often labelled in lb in the US and kg elsewhere; body-weight goals are tracked in either unit
- Cooking and baking: Recipes from different countries use grams, ounces or pounds; accurate conversion prevents failed bakes
- Shipping and postage: Carriers quote limits and prices in kg or lb depending on region
- Travel: Airline baggage allowances are quoted in kg almost everywhere except the US, where pounds are used
- E-commerce: Comparing product weights listed on international marketplaces
Why Weight Conversion Accuracy Matters
Small rounding errors compound quickly. If you round 1 kg to 2.2 lb instead of 2.20462 lb, a 100 kg load is out by about 0.5 lb; for shipping or nutrition that margin matters. The converter above uses full-precision factors (1 kg = 2.2046226218 lb) and formats the result cleanly, so you get laboratory-grade accuracy without the maths. All calculations happen locally in your browser, which means no data leaves your device and the tool works offline.
Frequently Asked Questions
How many pounds are in a kilogram?
One kilogram equals 2.20462 pounds. To convert kg to lb, multiply by 2.20462. To convert lb to kg, divide by 2.20462. Use our weight converter for instant results.
How many grams are in an ounce?
One avoirdupois ounce is exactly 28.349523125 grams. To convert ounces to grams, multiply by 28.35. For example, a 16 oz (1 lb) steak is 453.6 g.
What is a stone in kilograms?
One stone is 14 pounds, which equals 6.35029 kilograms. Stone is still the standard unit for body weight in the UK and Ireland. To convert stone to kg, multiply by 6.35.
How many pounds are in a US ton?
One US (short) ton is 2,000 pounds, which equals 907.185 kilograms. Note the metric tonne is 1,000 kg (2,204.6 lb), slightly heavier than the US ton.
Does the weight converter work offline?
Yes. Conversions run entirely in your browser using exact conversion factors. Once the page is loaded, you can use it offline with no server calls.
Why do I get different results to other calculators?
Most differences come from rounding. This tool uses full-precision factors and only rounds the final display. If a result still looks wrong, check that you selected the correct unit, for example US fluid ounce versus weight ounce, which are different measures.