Kilogram (kg) – The Fundamental SI Unit of Mass

Thekilogram (kg)is the base unit of mass in the International System of Units (SI). It is used worldwide in science, industry, and everyday commerce to quantify the amount of matter in an object.

History & Background

Originally defined by a physical prototype—a platinum-iridium cylinder stored in France—the kilogram has been redefined in 2019 in terms of the Planck constant for greater precision. This change reflects modern advances in metrology.

Conversion Factors

• 1 kg = 1,000 g
• 1 kg = 1,000,000 mg
• 1 kg ≈ 2.20462 lb

Applications

Kilograms are used to measure everything from groceries and personal body weight to industrial materials and scientific experiments.

Interesting Facts

The redefinition of the kilogram in 2019 marked a significant milestone in metrology, linking the unit to fundamental constants of nature.

Conclusion

As the primary unit of mass in the metric system, the kilogram is essential for precision measurement and underpins a vast array of scientific, commercial, and industrial applications.