Convert between different units of mass and weight with precision. Support for metric, imperial, and US customary units.
The earliest weight measurements were based on agricultural products: grains of wheat or barley. The ancient Egyptians used the deben (about 91 grams) for trading precious metals.
The pound originated from the Roman libra, approximately 327 grams. Different regions developed their own pound variations, leading to the complexity of modern weight systems.
In 1795, France introduced the gram as 1/1000th of a cubic centimeter of water. This became the foundation of the modern metric system, adopted worldwide for scientific and international trade.
The kilogram, the SI base unit of mass, is defined by the Planck constant. One kilogram is exactly 5.01845184190996 × 10²⁵ joule-seconds, ensuring global consistency.
Recipe conversion: 500g flour = 1.1 pounds
Weight loss goal: 0.5 kg/week = 1.1 pounds/week
Package weight: 25 kg = 55 pounds
Material specifications: 1000 kg = 1.102 metric tons