Pounds to Grams Calculator — lb to g Converter
Enter a weight in pounds and instantly convert to grams, kilograms, ounces, milligrams and stones — using the exact international avoirdupois definition of 1 lb = 453.59237 g.
lb
1 lb = 453.59237 g — the exact international avoirdupois definition
- 1
Conversion constant
453.59237The international avoirdupois pound equals exactly 453.59237 g. - 2
Grams = Pounds × 453.59237
1 × 453.59237 = 453.59237
How does this calculator work?
1 lb = 453.59237 g = 0.45359237 kg = 16 oz = 453,592.37 mg = 0.07143 stone. Multiply pounds by 453.59237 to get grams; divide grams by 453.59237 to reverse. The conversion is exact under the 1959 international avoirdupois pound definition.
Formula
How this is calculated
The avoirdupois pound is defined by international treaty as exactly 453.592 37 grams (the 1959 International Yard and Pound Agreement). This definition is exact — there is no rounding — so the conversions in this calculator are precise to full floating-point accuracy. One kilogram equals exactly 1,000 grams, and one ounce is exactly 1/16 of a pound, giving 1 oz = 28.349 523 125 g.
The stone is a UK and Irish unit equaling exactly 14 pounds (6.350 293 18 kg). It is not used in the US but is common for human body weight in the UK and Ireland. To convert from kilograms back to pounds, divide by 0.453 592 37 or equivalently multiply by 2.204 622 621 85.
For practical purposes, the quick approximation 1 lb ≈ 454 g or 1 kg ≈ 2.205 lb is accurate to within 0.1%. The calculator uses the full 8-significant-figure exact value, so results are suitable for engineering, laboratory and regulatory applications that require the highest accuracy.
Frequently asked questions
Exactly 453.59237 grams per pound. This is the internationally agreed exact value of the avoirdupois pound, defined in 1959. For quick mental arithmetic, 454 g is accurate to within 0.1%.
Exactly 1 kg = 1,000 g ÷ 453.59237 g/lb = 2.204622622… lb. The commonly quoted value of 2.2046 lb/kg is accurate to 4 decimal places, sufficient for most everyday uses.
Divide grams by 453.59237 to get pounds, or divide grams by 1,000 to get kilograms and then divide by 0.45359237. For example, 500 g ÷ 453.59237 = 1.1023 lb.
Also known as
TG we-Calculate Editorial Team. (2026). Pounds to Grams Calculator — lb to g Converter [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/pounds-to-grams-calculator
TG we-Calculate Editorial Team. "Pounds to Grams Calculator — lb to g Converter." TG we-Calculate. 2026. https://we-calculate.com/calculator/pounds-to-grams-calculator.
TG we-Calculate Editorial Team, "Pounds to Grams Calculator — lb to g Converter," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/pounds-to-grams-calculator
@misc{wecalculate_pounds_to_grams_calculator, title = {Pounds to Grams Calculator — lb to g Converter}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/pounds-to-grams-calculator}}, year = {2026}, note = {TG we-Calculate} }
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