About Weight Conversion
Weight and mass are among the most commonly converted quantities in daily life, cooking, fitness and trade. In everyday language "weight" and "mass" are used interchangeably, but they mean slightly different things: mass is the amount of matter in an object (measured in kilograms), while weight is the force gravity exerts on that mass (measured in newtons). For most practical purposes — grocery shopping, body weight, shipping — the two are treated the same, and this tool performs those conversions.
The metric system is used almost everywhere for mass. The United States still uses the imperial system — pounds and ounces — for body weight, food packaging and shipping. The United Kingdom uses a mix: metric for most goods but stone for human body weight. This tool supports both systems and their sub-units.
The 11 units supported
| Unit | Symbol | Kilograms |
|---|---|---|
| Microgram | µg | 0.000000001 |
| Milligram | mg | 0.000001 |
| Gram | g | 0.001 |
| Kilogram | kg | 1 |
| Metric ton (tonne) | t | 1000 |
| Ounce | oz | 0.028349523125 |
| Pound | lb | 0.45359237 |
| Stone | st | 6.35029318 |
| US ton (short ton) | ton | 907.18474 |
| Imperial ton (long ton) | long ton | 1016.0469088 |
| Carat | ct | 0.0002 |
Common conversions
| From | To | Factor |
|---|---|---|
| 1 kilogram | Pounds | 2.204622… approximately |
| 1 pound | Kilograms | 0.45359237 exactly |
| 1 ounce | Grams | 28.349523125 exactly |
| 1 stone | Pounds | 14 exactly |
| 1 metric ton | Kilograms | 1000 exactly |
| 1 carat | Milligrams | 200 exactly |
Common use cases
Cooking & Baking
Convert grams to ounces for international recipes.
Fitness & Training
Convert kg to lb for weight plates and body weight.
Shipping
Convert between kg, lb and tonnes for freight calculations.
Medicine & Pharmacy
Convert mg, µg and g for precise dosages.
Jewellery
Convert carats to grams and milligrams for gemstones.
Science & Lab
Convert between micro-, milli- and kilogram scales.
Privacy and accuracy
This weight converter runs entirely in your browser. All conversions use exact definitional factors, so the results are as precise as the input. Nothing is uploaded, stored or logged — safe for confidential weights, medical dosages and private shipping data.