Weight Converter – Convert Between All Weight Units
Free online weight converter. Instantly convert between kilograms, grams, milligrams, pounds, ounces, stones, and tons using SI-standard conversion factors.
Weight Converter
The weight converter above lets you switch instantly between metric and imperial weight units — kilograms, grams, milligrams, pounds, ounces, stones, and tons. Enter a value in any unit and get accurate results across all supported units simultaneously. All conversion factors follow the International System of Units (SI) and NIST-defined standards.
How to Use the Weight Converter
- Enter the weight value you want to convert in the input field.
- Select the unit you are converting from (e.g., kilograms).
- The converter instantly displays the equivalent value in all other units.
- For a specific pair, use DigiCalc's dedicated converters listed below.
Weight Unit Conversion Table
This table shows how common weight units relate to each other. The kilogram (kg) is the SI base unit of mass and serves as the reference point for all conversions.
| Unit | Symbol | In Kilograms | In Pounds |
|---|---|---|---|
| Milligram | mg | 0.000001 kg | 0.0000022 lb |
| Gram | g | 0.001 kg | 0.002205 lb |
| Kilogram | kg | 1 kg | 2.20462 lb |
| Metric Ton (Tonne) | t | 1,000 kg | 2,204.62 lb |
| Ounce (avoirdupois) | oz | 0.028350 kg | 0.0625 lb |
| Pound | lb | 0.453592 kg | 1 lb |
| Stone | st | 6.35029 kg | 14 lb |
| Short Ton (US) | ton | 907.185 kg | 2,000 lb |
Common Weight Units Explained
Kilogram (kg)
The kilogram is the SI base unit of mass, defined since 2019 by the Planck constant. Every country except the United States uses the kilogram as the standard unit for body weight, food, and commercial goods. One kilogram equals 1,000 grams or 2.20462 pounds.
Gram (g)
One gram is one-thousandth of a kilogram. Grams measure small quantities in cooking, nutrition labels, and laboratory measurements. A standard paperclip weighs approximately 1 gram; a teaspoon of sugar weighs about 4 grams.
Milligram (mg)
One milligram is one-thousandth of a gram. Pharmaceuticals and nutrition rely on milligrams for precise dosage — most medication tablets contain a specific milligram amount. One milligram equals 0.000035274 ounces. Use DigiCalc's mg to oz converter for this specific conversion.
Pound (lb)
The pound is the primary unit of everyday weight in the United States. One pound equals exactly 453.592 grams or 0.453592 kilograms. Body weight in the US is typically expressed in pounds; most other countries use kilograms.
Ounce (oz)
One ounce equals 1/16 of a pound, or 28.3495 grams. The US uses ounces for food portions, beverage sizes, and body weight fractions. The troy ounce (31.1035 g), used for precious metals, is different from the standard avoirdupois ounce.
Stone (st)
One stone equals 14 pounds or 6.35029 kilograms. The stone is used primarily in the United Kingdom and Ireland for expressing human body weight. A person weighing 70 kg is approximately 11 stone.
Metric Ton (Tonne)
One metric ton equals 1,000 kilograms or 2,204.62 pounds. The tonne is used for large commercial and industrial quantities — shipping cargo, agricultural produce, and construction materials. Use DigiCalc's tonne to kilograms converter for this pair.
Metric to Imperial Weight Conversions
The most commonly searched weight conversions involve switching between the metric system (kg, g) and the imperial system (lb, oz). Here are the key relationships:
| Metric | Imperial Equivalent |
|---|---|
| 1 kg | 2.20462 lb / 35.274 oz |
| 50 kg | 110.231 lb |
| 70 kg | 154.324 lb (average adult) |
| 100 kg | 220.462 lb |
| 1 g | 0.035274 oz |
| 100 g | 3.5274 oz |
| 500 g | 17.637 oz / 1.1023 lb |
| 1,000 g (1 kg) | 35.274 oz / 2.20462 lb |
Popular Weight Converters on DigiCalc
For detailed conversion tables, formulas, and real-world examples, use these dedicated tools:
- kg to lbs — Convert kilograms to pounds. The most searched weight conversion globally, used for body weight, luggage limits, and shipping.
- mg to oz — Convert milligrams to ounces. Essential for pharmaceutical, supplement, and precious metals use cases.
- g to kg — Convert grams to kilograms. Used in cooking, nutrition, and laboratory science.
- grams to mg — Convert grams to milligrams. Used for supplement and medication calculations.
- stone to lbs — Convert stone to pounds. Used in the UK and Ireland for body weight.
- ton to lbs — Convert tons to pounds. Used in commercial and industrial shipping contexts.
- tonne to kg — Convert metric tons to kilograms for large-scale weight calculations.
- mg to kg — Convert milligrams to kilograms across very large scale differences.
Weight vs Mass – What Is the Difference?
Weight and mass are related but not identical. Mass is the amount of matter in an object. It does not change regardless of location — a 70 kg person has 70 kg of mass on Earth, the Moon, and in space. Mass is measured in kilograms (SI).
Weight is the force exerted by gravity on a mass. On Earth's surface, weight in newtons equals mass × 9.81 m/s². A 70 kg person weighs approximately 686 newtons on Earth. On the Moon, where gravity is roughly 1/6 of Earth's, that same person weighs only about 114 newtons.
In everyday use — scales, food labels, body weight — "weight" and "mass" are used interchangeably because gravity is assumed constant at Earth's surface. Digital weight converters, including this one, convert between units of mass. The numbers on bathroom scales, nutrition labels, and shipping documents are technically measurements of mass expressed as weight under standard gravity.
Metric vs Imperial System
The metric system (SI) uses a base-10 structure — kilograms, grams, milligrams — making calculations straightforward. Every unit is a power of ten multiplied by the base. Every country in the world officially adopts the metric system for science, medicine, and international trade.
The imperial system — pounds, ounces, stones — uses historical ratios (16 oz in a pound, 14 lb in a stone) with no consistent multiplier. The United States is the only major economy where imperial units remain standard for everyday consumer use. The UK uses a hybrid: kilograms officially but stones and pounds for body weight informally.
According to Google Keyword Planner data, searches for "kg to lbs" alone exceed 1.5 million per month globally. This mismatch between systems explains why weight converters rank among the most-searched conversion tools online. When a US recipe calls for 1 lb of flour, a cook in Germany needs to know that equals 453 grams. When a UK gym records body weight in stones, an app syncing internationally needs kilogram equivalents.
Limitations of Digital Weight Converters
- This converter uses mass units, not force units. If you need to convert kilograms to newtons (weight force), use DigiCalc's lbs to newtons converter instead.
- Standard vs troy ounce: This converter uses the avoirdupois ounce (28.3495 g). For gold, silver, and precious metals, the troy ounce (31.1035 g) applies. Always confirm which ounce definition your context requires.
- Fluid ounces are volume, not mass: One fluid ounce is not the same as one weight ounce. Fluid ounces measure volume and require density to convert to mass.
- Scale precision varies: A bathroom scale reading of 70.0 kg carries different precision than a laboratory balance. This converter is mathematically exact; the real-world accuracy depends on the measuring instrument used.