Weight Conversion
Your European supplier shipped a pallet listed at 450 kg, but your US logistics partner bills by the pound. A recipe calls for 8 oz of flour, yet your digital scale only displays grams. These situations show why weight conversion between metric and imperial systems is a daily necessity for trade, cooking, fitness, and science.
The calculator above handles the arithmetic instantly. Enter any value in grams, kilograms, ounces, pounds, stones, or tons, and it returns the equivalent across all other units.
How Do You Convert Kilograms to Pounds?
The international avoirdupois pound is legally defined as exactly 0.45359237 kilograms. To convert kilograms to pounds, multiply by 2.20462.
Example:
75 kg × 2.20462 = 165.35 lbs
To convert pounds back to kilograms, divide by 2.20462 or multiply by 0.453592.
Example:
180 lbs × 0.453592 = 81.65 kg
Common Weight Conversion Formulas
Use these multipliers to move between systems without a cheat sheet:
- Grams to ounces: multiply by 0.035274
- Ounces to grams: multiply by 28.3495
- Pounds to kilograms: multiply by 0.453592
- Kilograms to pounds: multiply by 2.20462
- Stones to kilograms: multiply by 6.35029
- Metric tons to pounds: multiply by 2,204.62
- US tons to kilograms: multiply by 907.185
For scientific work, the gram is defined by the International Bureau of Weights and Measures (BIPM) using fundamental physical constants, while the US customary pound is maintained by the National Institute of Standards and Technology (NIST).
Metric and Imperial Units Reference Table
| Unit | Grams | Ounces | Pounds | Kilograms |
|---|---|---|---|---|
| 1 gram | 1 | 0.0353 | 0.0022 | 0.001 |
| 1 ounce | 28.35 | 1 | 0.0625 | 0.0283 |
| 1 pound | 453.59 | 16 | 1 | 0.4536 |
| 1 kilogram | 1,000 | 35.27 | 2.2046 | 1 |
| 1 stone | 6,350.29 | 224 | 14 | 6.35 |
| 1 metric ton | 1,000,000 | 35,274 | 2,204.62 | 1,000 |
| 1 US ton | 907,184.7 | 32,000 | 2,000 | 907.18 |
Values are rounded to two decimal places except where exact.
Quick Mental Math for Weight Conversion
Precise figures require a calculator, but these shortcuts handle everyday estimates:
- kg to lbs: double the kilograms and add 10%.
70 kg → 140 + 14 = 154 lbs (exact: 154.32). - lbs to kg: divide by 2 and subtract 10%.
200 lbs → 100 – 10 = 90 kg (exact: 90.72). - oz to g: multiply by 30 and subtract 5%.
10 oz → 300 – 15 = 285 g (exact: 283.5).
Troy Ounces vs Avoirdupois Ounces
Precious metals use the troy ounce, which is heavier than the everyday avoirdupois ounce.
- 1 troy oz = 31.1034768 g
- 1 avoirdupois oz = 28.3495 g
Mixing these up shifts gold and silver valuations by roughly 10%. If a commodity price is quoted in troy ounces but you weigh the metal on a kitchen scale calibrated in avoirdupois units, the conversion will be inaccurate.
Grams, Milligrams, and Micrograms in Science
In laboratory and medical contexts, conversions cascade by factors of 1,000:
- 1 gram = 1,000 milligrams
- 1 milligram = 1,000 micrograms (µg or mcg)
- 1 gram = 1,000,000 micrograms
A medication dosed at 500 µg equals 0.5 mg and 0.0005 g. Because errors in decimal placement can have serious consequences, scientists use scientific notation or dedicated scales rather than manual conversion.
Weight Conversion in Professional Contexts
Different industries default to different units. Pharmaceuticals and precious metals often use grams and milligrams. Global freight relies on kilograms and metric tons. Fitness coaching in the United States tracks pounds, while medical dosing typically requires metric units. Understanding which system a sector uses prevents costly errors, especially when shipping documents list net weight in kilograms but customs forms expect pounds.