Weight Converter
Convert between metric and imperial weight units — mg, g, kg, tonnes, ounces, pounds, and stones. Precise results instantly.
How to calculate Weight
Weight conversion is frequently needed in cooking, fitness, shipping, and medicine. The metric and imperial systems handle weight very differently, which can cause confusion when switching between countries.
The metric system: 1000 mg = 1 g, 1000 g = 1 kg, 1000 kg = 1 metric ton. Pharmacology uses milligrams for drug dosing; grocery shopping uses grams and kilograms; heavy freight uses metric tons.
The imperial system: 16 oz = 1 lb, 14 lb = 1 stone. The stone is primarily used in the United Kingdom for body weight. Ounces and pounds dominate American recipes and product labels.
Key conversions: 1 kg = 2.2046 lb, 1 lb = 453.6 g, 1 oz = 28.35 g, 1 stone = 6.350 kg.
In medicine, precise weight conversion is critical — medication dosing is often weight-based, and an error between pounds and kilograms can cause a serious overdose. This calculator covers all seven common weight units from milligrams to metric tons with high precision.