Quick answer
Weight (mass) converts through kilograms. 1 pound equals exactly 453.59237 grams, or 0.45359237 kg.
Enter a value and choose the units and decimals. The calculator returns the converted mass.
How to use the Weight Converter
- Enter value.
- Choose from: Microgram (µg), Milligram (mg), Gram (g), Kilogram (kg), Metric tonne (t) and Ounce (oz) and 6 more.
- Choose to: Microgram (µg), Milligram (mg), Gram (g), Kilogram (kg), Metric tonne (t) and Ounce (oz) and 6 more.
- Enter decimal places (between 0 and 10). It starts at 4.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Value | A number | — |
| From | Choose one: Microgram (µg); Milligram (mg); Gram (g); Kilogram (kg); Metric tonne (t); Ounce (oz); Pound (lb); Stone (st); … | Starts at Microgram (µg) |
| To | Choose one: Microgram (µg); Milligram (mg); Gram (g); Kilogram (kg); Metric tonne (t); Ounce (oz); Pound (lb); Stone (st); … | Starts at Milligram (mg) |
| Decimal places | A number | ≥ 0, ≤ 10, starts at 4 |
Formula and method
Formula
result = value × (factor of source ÷ factor of target), base unit: kilogram
IEEE-754 double precision; displayed to the chosen number of decimal places (default 4). Very small or large results are shown in scientific notation.
Every unit is defined by an exact or published factor to the base unit (kilogram). The value is multiplied by the source factor and divided by the target factor.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Value = 1; From = Pound (lb); To = Gram (g); Decimal places = 5.
| Result | Value |
|---|---|
| Pound (lb) → Gram (g) | 453.59237 |
| Input | 1 Pound (lb) |
Example 2
Inputs: Value = 1; From = Kilogram (kg); To = Pound (lb); Decimal places = 4.
| Result | Value |
|---|---|
| Kilogram (kg) → Pound (lb) | 2.2046 |
| Input | 1 Kilogram (kg) |
Example 3
Inputs: Value = 16; From = Ounce (oz); To = Pound (lb); Decimal places = 4.
| Result | Value |
|---|---|
| Ounce (oz) → Pound (lb) | 1 |
| Input | 16 Ounce (oz) |
The first line is the headline result (pound (lb) → Gram (g)). Below it the weight Converter lists input, which describe the same case from other angles. IEEE-754 double precision; displayed to the chosen number of decimal places (default 4). Very small or large results are shown in scientific notation.
Unit reference
Each unit expressed in the base unit used for the calculation. Conversions go through this base unit, so any unit can be converted to any other in the table.
| Unit | Equals (in kilogram) |
|---|---|
| Microgram (µg) | 1e-9 |
| Milligram (mg) | 0.000001 |
| Gram (g) | 0.001 |
| Kilogram (kg) | 1 |
| Metric tonne (t) | 1000 |
| Ounce (oz) | 0.02834952313 |
| Pound (lb) | 0.45359237 |
| Stone (st) | 6.35029318 |
| US short ton | 907.18474 |
| UK long ton | 1016.046909 |
| Carat (ct) | 0.0002 |
| Grain (gr) | 0.00006479891 |
Key conversions
1 kg = 2.20462 lb, 1 oz = 28.3495 g, 1 stone = 14 lb = 6.35 kg and 1 US ton = 2,000 lb. A metric tonne is 1,000 kg. A troy ounce is 31.1035 g.
Searches such as 'mg to ml' are volume-and-weight questions that depend on the liquid's density. This page converts mass units only (milligrams to kilograms, pounds to ounces); for flour, sugar and similar ingredients use the Cooking Ingredient Converter.
Mass versus weight
Strictly, kg and lb are units of mass, while weight is a force. In everyday use they are treated as interchangeable on Earth.
How the result changes with value
Holding every other input at the first worked example, this table changes only value. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Value | Pound (lb) → Gram (g) | Input |
|---|---|---|
| 0.5 | 226.79619 | 0.5 Pound (lb) |
| 1 | 453.59237 | 1 Pound (lb) |
| 2 | 907.18474 | 2 Pound (lb) |
| 4 | 1,814.36948 | 4 Pound (lb) |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Value: left empty shows "Enter value." beside that field and no result.
Choosing between the Weight Converter and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Water Weight Calculator](/health/water-weight-calculator/) | volume, volume unit and water temperature | Weight |
| [Gold Weight Calculator](/construction/gold-weight/) | volume and unit | Mass |
| [Ideal Weight Calculator](/health/ideal-weight-calculator/) | units, sex and height | Ideal weight (Devine) |
| [Weight Gain Calculator](/health/weight-gain/) | units and gain per week | Daily calorie surplus |
| [Pipe Weight Calculator](/construction/pipe-weight/) | outside diameter, wall thickness and length | Pipe weight |
Background: unit conversion
Many customary units are defined exactly in terms of metric ones: since the 1959 International Yard and Pound Agreement an inch is exactly 2.54 cm and a pound is exactly 0.45359237 kg (NIST SP 811 lists these). So most length and mass conversions are exact apart from the rounding of the displayed result.
To convert, multiply the value by the source unit's factor to reach the base unit, then divide by the target unit's factor; the unit table on this page lists every factor used. Temperature and fuel economy are the exceptions, because they are not simple multiples.
Assumptions and limitations
- Negative values are allowed
- Zero converts to zero (except L/100 km, where zero is invalid)
- Units from different quantities cannot be converted
- Very large or tiny results switch to exponent notation
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for value to confirm this.
Frequently asked questions
How many pounds is 70 kg?
70 kg is about 154.3 lb (70 × 2.20462).
How many grams in an ounce?
An avoirdupois ounce is 28.3495 g, so a 100 g bar is about 3.5 oz.
What is a stone?
A British unit of 14 pounds.
What does the Weight Converter calculate?
Convert kilograms, pounds, ounces, stone and more. It returns Pound (lb) → Gram (g) and Input.
What formula does the Weight Converter use?
result = value × (factor of source ÷ factor of target), base unit: kilogram. Every unit is defined by an exact or published factor to the base unit (kilogram).
What is an example of a weight result?
With value 1, from Pound (lb), to Gram (g) and decimal places 5, the pound (lb) → Gram (g) is 453.59237.
Where does the method come from?
The method follows: NIST SP 811 (2008), Appendix B.8: avoirdupois pound = 0.45359237 kg exactly; BIPM SI Brochure (9th ed.).
Related calculators
Sources
- NIST SP 811 (2008), Appendix B.8: avoirdupois pound = 0.45359237 kg exactly
- BIPM SI Brochure (9th ed.)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.