Weight Unit Converter
Instantly convert between mg, g, kg, tonnes, ounces, pounds and stone.
Weight Converter: kg, Pounds, Ounces and More in One Place
Weight units are a constant source of confusion across shopping, shipping pricing, engineering calculations, and international technical documents. Do you need to convert between kilograms and pounds, or between ounces and grams? The weight converter calculates 7 units simultaneously and saves you from repetitive manual work.
What Is a Weight Converter and Why Is It Needed?
The metric system (mg, g, kg, t) and the British-American system (oz, lb, st) are used simultaneously in different countries and sectors. Incorrect unit conversion can have serious consequences, from excess shipping charges to medication dosing errors. The tool uses conversion factors compliant with the ISO 31-3 standard.
All conversions are performed through kilograms: the entered value is first converted to kg, then to the target unit. This approach minimises cumulative rounding errors.
How to Use. Step by Step
Required Inputs
- The numeric value you want to convert
- Source unit (mg / g / kg / t / oz / lb / st)
Formula / Calculation Logic
The value is first converted to kg: kg = input × kg_factor. Then converted to the target unit: result = kg / target_kg_factor. Example: 5 lb → kg: 5 × 0.453592 = 2.268 kg.
Weight Unit Conversion Table (mg, g, kg, t, oz, lb, st)
| Unit | mg | g | t | oz | lb | st |
|---|---|---|---|---|---|---|
| 1 Kilogram (kg) | 1,000,000 | 1,000 | 0.001 | 35.274 | 2.2046 | 0.1575 |
| 1 Gram (g) | 1,000 | 1 | 0.000001 | 0.03527 | 0.002205 | — |
| 1 Tonne (t) | — | 1,000,000 | 1 | 35,274 | 2,204.6 | 157.5 |
| 1 Pound (lb) | 453,592 | 453.592 | 0.000454 | 16 | 1 | 0.0714 |
| 1 Ounce (oz) | 28,350 | 28.35 | — | 1 | 0.0625 | — |
| 1 Stone (st) | — | 6,350 | 0.00635 | 224 | 14 | 1 |
Tips for Accurate Results
- When entering ounces, be aware whether you are using a standard ounce (avoirdupois) or a troy ounce; the difference matters for precious metal transactions.
- In the US, "ton" typically refers to the short ton (907.18 kg) — do not confuse it with the metric tonne (1,000 kg).
- For shipping measurements, first confirm which unit the carrier uses; selecting the wrong unit can create a charge discrepancy.
- For very small values (pharmaceuticals, chemistry), μg (micrograms) may be required instead of mg; this tool does not support μg.