About the Weight Converter
Weight Converter changes a mass between milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, US short tons and UK long tons. Enter a number, choose the unit it is in and read every other unit at once. The factors are the exact international definitions, so 1 lb is exactly 0.45359237 kg. Use it for body weight, luggage limits, recipes, postage, shipping and school work, or whenever a label uses a different system from the one you know.
Updated October 2026
How to use the Weight Converter
- 1Type the a weight or mass you want to convert.
- 2Choose the unit it is in from the From unit list.
- 3Read the result in every other unit straight away.
- 4Press Copy to keep the answer, or change the number to try another.
When you need a a weight or mass converter
Weight Converter changes a mass between milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, US short tons and UK long tons. People often say weight when they mean mass. Strictly, kilograms and pounds measure mass, which does not change, while weight is the force of gravity on that mass. For everyday use on Earth the two are used as the same thing, and this page converts mass.
Units and what they mean
The three kinds of ton are a common trap. A US ton is 2,000 lb (about 907 kg), a UK ton is 2,240 lb (about 1,016 kg) and a metric tonne is 1,000 kg. When a document just says ton, check which country it comes from before you convert.
- Gram and kilogram: the everyday metric units, 1,000 g per kg
- Ounce and pound: 16 oz per lb, used for food, post and body weight in the US
- Stone: 14 lb, still used for body weight in the UK and Ireland
- US short ton (2,000 lb), UK long ton (2,240 lb) and metric tonne (1,000 kg)
Tips for accurate results
Airlines, couriers and gyms mix units freely. Convert to the unit the limit is set in, then compare. For luggage, 23 kg is about 50.7 lb, and a 20 kg plate is about 44.1 lb.
Round only at the end of a calculation. If you convert and then convert again, keep the full number in between so small errors do not add up.
Related conversions
Ounces in this page are avoirdupois ounces (mass). Fluid ounces measure volume and are different. For those use Volume Converter. Related tools: Length Converter, Kg to Lbs Converter, Grams to Ounces Converter and Stones to Pounds Converter.
Features
- 9 units in one list
- Every result shown at once
- Exact factors, no rounding until you read it
- Works with decimals and negative-free values
- Copy button for the answer
- Calculated in your browser, so nothing is uploaded.
Frequently asked questions
How do I convert a weight or mass?
Type the number, pick the unit you start with and read the answer in every other unit below. Each unit is stored as an exact factor of one base unit, so a result is the number times its factor divided by the target unit's factor.
How many pounds are in a kilogram?
About 2.20462 pounds. Exactly, 1 lb is 0.45359237 kg, so 1 kg is 1 divided by that number.
How many ounces are in a pound?
16 ounces.
What is a stone in kg?
One stone is 14 pounds, which is about 6.35 kg.
Is the result exact?
The factors used are the official or standard definitions, so the maths is exact. The page rounds what it shows to about 10 significant digits so numbers stay readable.
Does it work on my phone?
Yes. The page is built for small screens, with large inputs and a list of units you can scroll.
Is anything sent to a server?
No. The conversion is plain arithmetic in your browser, so nothing you type leaves your device.