Weight & Mass Units — Complete Guide

By Unitafy · March 2026 · 5 min read

Weight and mass are often used interchangeably in daily life, but they are technically different. Mass is the amount of matter (measured in kg), while weight is the force of gravity on that mass. For everyday purposes, the difference rarely matters — but it's good to know.

Main Weight/Mass Units

Kilogram (kg) — The Global Standard

The SI base unit of mass. Used worldwide in science, medicine, and daily life. Body weight, food, and shipping all use kg in most countries.

Pound (lb) — The US Standard

Equal to 453.592 grams. The primary weight unit in the United States. US residents typically measure body weight in pounds; most other countries use kg.

Stone — UK Body Weight

Equal to 14 pounds or 6.35 kg. Still commonly used in the UK and Ireland for body weight. A person weighing 11 stone 7 lbs = 161 lbs = 73 kg.

Gram (g) — Precision Measurement

Equal to 1/1000 kg. Used for cooking ingredients, medicine, and precious metals. Gold prices are quoted per gram worldwide.

Weight Conversion Table

kglbsstonegrams
12.2050.1571,000
511.020.7875,000
1022.051.57510,000
50110.27.8750,000
70154.311.0270,000
100220.515.75100,000

Body Weight Reference

  • Healthy adult (60 kg): 132 lbs / 9 stone 6 lbs
  • Average Indian male (65 kg): 143 lbs / 10 stone 3 lbs
  • Newborn baby (3 kg): 6.6 lbs

💪 Gym conversion: 1 kg ≈ 2.2 lbs. So a 100 kg bench press is about 220 lbs. Most gym equipment in India uses kg; US gyms use lbs.