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Weight Converter

Weight conversion between common units uses kilograms as the base: 1 lb = 0.453592 kg, 1 oz = 0.0283495 kg, 1 g = 0.001 kg, and 1 st = 6.35029 kg. Enter a weight in any unit to convert to all other supported units instantly. The converter handles pounds, kilograms, ounces, grams, and stone.

Quick Answer

1 pound equals 0.4536 kilograms, 16 ounces, 453.592 grams, and 0.0714 stone.

Common Examples

Input Result
150 lb 68.0389 kg / 2,400 oz / 68,038.86 g / 10.7143 st
75 kg 165.3467 lb / 2,645.55 oz / 75,000 g / 11.8110 st
500 g 1.1023 lb / 0.5 kg / 17.637 oz / 0.0787 st
10 st 140.0 lb / 63.503 kg / 2,240.0 oz / 63,502.9 g

How It Works

All weight conversions use kilograms as the intermediate base unit. The process is: convert the input value to kilograms, then convert from kilograms to each target unit.

Conversion factors to kilograms:

  • 1 pound (lb) = 0.453592 kg
  • 1 kilogram (kg) = 1 kg
  • 1 ounce (oz) = 0.0283495 kg
  • 1 gram (g) = 0.001 kg
  • 1 stone (st) = 6.35029 kg

Conversion factors from kilograms:

  • kg to lb: divide by 0.453592 (or multiply by 2.20462)
  • kg to oz: divide by 0.0283495 (or multiply by 35.274)
  • kg to g: divide by 0.001 (or multiply by 1000)
  • kg to st: divide by 6.35029 (or multiply by 0.157473)

These conversion factors are based on the International System of Units (SI) definitions. One pound is defined as exactly 0.45359237 kilograms, and one stone equals exactly 14 pounds.

Worked Example

To convert 150 pounds to kilograms: 150 x 0.453592 = 68.0389 kg. From that kg value to ounces: 68.0389 / 0.0283495 = 2,400 oz. To grams: 68.0389 / 0.001 = 68,038.86 g. To stone: 68.0389 / 6.35029 = 10.7143 st. This confirms the well-known relationship that 1 stone = 14 pounds, since 150 / 14 = 10.7143.

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Frequently Asked Questions

How many ounces are in a pound?
There are exactly 16 ounces in one pound. This is the avoirdupois ounce used for everyday weight measurements. Troy ounces (used for precious metals) have a different conversion: 1 troy ounce = 31.1035 grams.
What is a stone and where is it used?
A stone (st) equals exactly 14 pounds or approximately 6.35 kilograms. It is commonly used in the United Kingdom and Ireland for measuring body weight. For example, a person weighing 154 pounds would be described as 11 stone.
What is the difference between mass and weight?
In everyday use, mass and weight are treated interchangeably. Technically, mass (measured in kilograms) is a property of matter, while weight is the force of gravity on that mass. On Earth's surface, this distinction rarely matters for practical conversions.
Why do some countries use pounds and others use kilograms?
The United States primarily uses the imperial system (pounds, ounces), while most other countries use the metric system (kilograms, grams). The UK uses a mix of both, with stone and pounds for body weight but kilograms for most other purposes.
How accurate are these conversions?
The conversion factors used here are precise to 6 significant digits, matching the internationally defined values. For everyday purposes, this level of precision is more than sufficient. Scientific applications may require additional decimal places.