Weight Converter for Kilograms, Pounds, Ounces, Stone and Grams
Convert kilograms, pounds, ounces, stone, grams, milligrams, and metric tonnes with instant results.
Convert Weight
Enter a value, choose the starting unit, and select the unit you want.
How to Use the Weight Converter
The weight converter changes a value from one supported unit to another. Enter the amount, choose the starting unit, then select the unit you need. The result updates instantly.
- Enter a value. Use zero or any positive number.
- Select the starting unit. Choose milligrams, grams, kilograms, metric tonnes, ounces, pounds, or stone.
- Select the target unit. The converted value appears immediately.
- Use Swap Units. Reverse the source and target units with one click.
- Check the other-unit values. The tool also shows the same amount across all supported units.
Popular shortcuts make common weight conversions such as kilograms to pounds, pounds to kilograms, kilograms to stone, and grams to ounces faster to select.
How Weight Conversion Works
The calculator uses grams as its internal base. It first converts the entered amount to grams, then converts that gram value into the selected target unit.
Value in grams = Input Value × Source Unit Factor
Converted Value = Value in grams ÷ Target Unit Factor
This method keeps calculations consistent across all supported unit pairs.
Weight Conversion Formula
A conversion factor describes the relationship between two units. The kilogram is the SI base unit of mass, while common non-SI units such as pounds and ounces are defined through standard conversion relationships.
Kilograms = Pounds × 0.45359237
Pounds = Kilograms ÷ 0.45359237
Metric Weight and Mass Units
Metric mass units use decimal relationships. The kilogram is the SI base unit of mass, and smaller or larger metric units scale by powers of ten.
- 1,000 milligrams = 1 gram
- 1,000 grams = 1 kilogram
- 1,000 kilograms = 1 metric tonne
- 1 kilogram = 1,000,000 milligrams
The decimal structure makes metric conversions simple and predictable.
Pounds, Ounces and Stone
Pounds, ounces, and stone are commonly used outside the metric system. Their relationships are fixed and can be converted directly.
- 16 ounces = 1 pound
- 14 pounds = 1 stone
- 1 pound = exactly 0.45359237 kilograms
- 1 ounce = 28.349523125 grams
- 1 stone = 6.35029318 kilograms
Common Weight Conversion Chart
| Starting Unit | Equivalent Amount |
|---|---|
| 1 gram | 1,000 milligrams |
| 1 kilogram | 1,000 grams |
| 1 metric tonne | 1,000 kilograms |
| 1 pound | 16 ounces |
| 1 pound | 0.45359237 kilograms |
| 1 ounce | 28.349523125 grams |
| 1 stone | 14 pounds |
| 1 stone | 6.35029318 kilograms |
How to Convert Kilograms to Pounds
Divide kilograms by 0.45359237, or multiply by approximately 2.20462262.
Pounds = Kilograms ÷ 0.45359237
75 kg to pounds
75 ÷ 0.45359237 = 165.346697 lb
How to Convert Pounds to Kilograms
Multiply pounds by 0.45359237.
Kilograms = Pounds × 0.45359237
150 lb to kilograms
150 × 0.45359237 = 68.0388555 kg
How to Convert Grams to Ounces
One ounce equals 28.349523125 grams. Divide grams by that factor to get ounces.
Ounces = Grams ÷ 28.349523125
500 g to ounces
500 ÷ 28.349523125 = 17.636981 oz
How to Convert Ounces to Grams
Multiply ounces by 28.349523125.
Grams = Ounces × 28.349523125
12 oz to grams
12 × 28.349523125 = 340.194278 g
How to Convert Kilograms to Stone
One stone equals 6.35029318 kilograms. Divide kilograms by this factor to get stone.
Stone = Kilograms ÷ 6.35029318
75 kg to stone
75 ÷ 6.35029318 = 11.810477 st
When stone is selected as the target unit, the calculator also shows a stone-and-pounds style result for practical reading.
Metric vs Imperial Weight Units
Metric mass units scale in powers of ten, so converting between milligrams, grams, kilograms, and tonnes is straightforward.
Pounds, ounces, and stone use different fixed relationships. One pound has 16 ounces, while one stone has 14 pounds. A unit converter helps when moving between these systems.
Weight vs Mass
In physics, mass and weight are different quantities. Mass describes the amount of matter in an object, while weight is a force that depends on gravity.
Everyday searches commonly use the word "weight" for kilograms, pounds, ounces, and stone, so this tool follows that familiar wording while performing mass-unit conversions.
Common Weight Conversion Mistakes
- Confusing ounces with fluid ounces. Ounces measure mass here; fluid ounces measure volume.
- Using a rounded pound factor too early. Keep the exact factor during calculation and round the final display.
- Confusing stone with pounds. One stone equals 14 pounds.
- Mixing metric tonnes with US tons. One metric tonne equals 1,000 kilograms and is not the same as a US short ton.
- Reversing the conversion factor. Check whether the formula requires multiplication or division.
Weight Converter FAQs
What units does this weight converter support?
It supports milligrams, grams, kilograms, metric tonnes, ounces, pounds, and stone.
How many pounds are in one kilogram?
One kilogram is approximately 2.20462262 pounds.
How many kilograms are in one pound?
One pound equals exactly 0.45359237 kilograms.
How many ounces are in one pound?
One pound contains 16 ounces.
How many pounds are in one stone?
One stone contains 14 pounds.
Does oz mean fluid ounce here?
No. Ounce (oz) in this calculator is a mass unit. Fluid ounce is a volume unit.
Does the tool support negative weights?
No. It accepts zero and positive values for everyday mass conversion.
Sources and Calculation Methodology
Conversion definitions reviewed September 13, 2026.
The calculator uses grams as its internal base unit. Metric values are converted through decimal SI relationships, while pounds, ounces, and stone use standard fixed conversion factors.
- BIPM: SI Base Unit, Kilogram
- BIPM: International System of Units
- NIST: Guide to SI Units and Conversion Factors
- NIST: Approximate Conversions from US Customary Measures to Metric
For other measurement types, use the Length Converter, Temperature Converter, or Volume Converter.