Weight Converter
Convert between metric and imperial weights instantly — including stone, which is still widely used in the UK for body weight.
WEIGHT CONVERTER
Metric
Imperial & UK Body Weight
Enter a weight to see it in stone and pounds
Enter a weight to see a real-world comparison
Common weights — click to load
Step-by-step solution
Type a weight to see the conversion working
Key conversion facts
Real-world weights
Weight Converter Explained
Core concepts, classroom applications, and plain-English explanations for all audiences.
Where you'll actually use this
Packing for a holiday: your airline allows 23 kg — but the bathroom scales you own show stone and pounds. Boxing weight classes are in kg but American boxing uses pounds. US recipes give ingredient quantities in ounces and cups. And when a baby is born in the UK, the birth weight is often given in both pounds/ounces and kg — usually by different family members.
Worked example
"Your luggage weighs 23.4 kg. Your airline limit is 50 lbs. Are you over?"
23.4 kg × 2.20462 = 51.59 lbs
Limit: 50 lbs
Result: Yes — 1.59 lbs over. Remove about 720 g from the bag
Quick rule: 1 kg ≈ 2.2 lbs. Multiply kg by 2.2 for a fast estimate.
Key weight contexts
- → Stone and pounds: Used in the UK for body weight. 1 stone = 14 lbs = 6.35 kg. "10 stone 5" = 10×14 + 5 = 145 lbs = 65.77 kg.
- → Cooking ounces: US recipes use weight ounces. 8 oz of cream cheese = 227 g. (Different from fluid ounces — watch out!)
Important science distinction
In everyday life we say "weight" but in physics, kg is mass. True weight is measured in Newtons (force of gravity on the mass). On the Moon you'd weigh about 1/6th as much but your mass — your kg — stays exactly the same.
Understanding Weight Conversion
Whether you're baking, lifting weights, or studying for your GCSEs, understanding how to convert between different units of weight (or more accurately, mass!) is a crucial skill. Our Weight Converter makes it simple to switch between metric units like milligrams, grams, kilograms, and tonnes, and imperial units such as ounces, pounds, and stone.
This tool isn't just a calculator; it's designed to help you grasp the relationships between these units. Just type a value into any field, and watch all other units update instantly. We also provide clear, step-by-step working for each conversion, along with real-world comparisons to give you a better sense of scale.
Common mistakes to avoid
- Mass and weight are the same thing:Mass is the amount of matter in an object (measured in kg), which stays constant. Weight is the force of gravity acting on that mass (measured in Newtons), which changes depending on the gravitational field (e.g., you'd weigh less on the Moon). Mass is a fundamental property of an object, while weight is a force. On Earth, we often use 'weight' informally to mean mass.
- I weigh 10 pounds and 5 stone:Stone and pounds are both imperial units of mass. There are 14 pounds in 1 stone. You wouldn't typically combine them like this; you'd either say '10 stone 5 pounds' or convert the entire amount to pounds or stone. To express a weight using both units, you'd say 'X stone Y pounds', where Y is less than 14. For example, '10 stone 5 pounds' (which is 145 pounds).
- To convert grams to kilograms, I multiply by 1000:Kilograms are larger units than grams. There are 1000 grams in 1 kilogram. To convert a smaller unit (grams) to a larger unit (kilograms), you need to divide. To convert grams to kilograms, you divide by 1000. For example, 5000g ÷ 1000 = 5kg.
- 1 kilogram is exactly 2 pounds:While 2 pounds is a common rough estimate, the precise conversion factor is slightly higher. Using '2' can lead to noticeable errors, especially for larger weights. 1 kilogram is approximately 2.20462 pounds. For accuracy, it's best to use the more precise conversion factor or a converter tool.