Weight Converter
Convert between Kilogram, Pound, Ounce, Gram, Milligram, Stone, Metric Ton, US Ton, and Imperial Ton instantly. See all results at once with formulas.
Common Weight Reference Table
| Description | kg | lb | oz | g |
|---|---|---|---|---|
| 1 Kilogram | 1 | 2.2046 | 35.274 | 1,000 |
| 1 Pound | 0.4536 | 1 | 16 | 453.59 |
| 1 Ounce | 0.02835 | 0.0625 | 1 | 28.35 |
| 1 Stone | 6.3503 | 14 | 224 | 6,350.3 |
| 1 Metric Ton | 1,000 | 2,204.6 | 35,274 | 1,000,000 |
| 1 US Ton (short) | 907.19 | 2,000 | 32,000 | 907,185 |
| 1 Imperial Ton (long) | 1,016.0 | 2,240 | 35,840 | 1,016,047 |
Built-In Features
All Units at Once
See your weight value converted to all nine units simultaneously. Kilogram, Pound, Ounce, Gram, Milligram, Stone, Metric Ton, US Ton, and Imperial Ton are all displayed together so you never need to run multiple conversions.
Real-Time Results
Conversions update instantly as you type. No need to press a button or wait for a page reload. Just start entering a number and watch every unit update in real time.
Formulas & Reference Table
Every conversion shows the exact formula used so you can understand the math. A built-in reference table provides quick lookups for common weight equivalences across metric and imperial systems.
Getting Started with Weight Converter
- Enter the weight or mass value you want to convert in the input field.
- Select the source unit (e.g., Kilogram, Pound, Ounce) from the "From" dropdown.
- Optionally select a target unit in the "To" dropdown, or view all conversions at once in the result area below.
- Use the swap button (↔) to quickly reverse the from and to units.
- Click the "Copy" button to copy the full conversion result to your clipboard.
- Click "Clear" to reset all fields and start a new conversion.
When dealing with precious metals, always use troy ounces (31.1035 g), not avoirdupois ounces (28.3495 g). Gold, silver, and platinum are universally priced per troy ounce, which is about 10% heavier than a regular ounce. Mixing them up means a significant pricing error on every transaction.
For a quick kg-to-lbs estimate, multiply by 2.2, not 2.0. Using 2.0 gives you a result that is roughly 10% too low. For example, 70 kg is actually 154.3 lbs, not 140 lbs. That difference matters for luggage limits, shipping costs, and dietary tracking.
Understanding Weight and Mass Measurement
Weight and mass are among the most essential measurements in daily life, science, commerce, and industry. Whether you are weighing ingredients for a recipe, checking your body weight, shipping a package overseas, or performing laboratory experiments, understanding the different units of weight and how they relate to one another is critically important. Two major systems dominate global weight measurement: the metric system and the imperial system, each with its own history, logic, and set of units.
The metric system of mass measurement is built on the gram as its base unit, with the kilogram serving as the primary standard. One kilogram equals exactly one thousand grams, and one metric ton equals one thousand kilograms. This clean decimal structure makes the metric system remarkably easy to work with: converting between grams, kilograms, and metric tons requires only moving the decimal point. The metric system was formalized during the French Revolution in the 1790s as part of an effort to create a universal, rational system of measurement. Today, the kilogram is defined by the Planck constant, a fundamental constant of quantum mechanics, making it one of the most precisely defined units in all of science. Virtually every country in the world uses the metric system as its official standard for trade, science, and regulation.
The imperial and US customary systems use pounds and ounces as their primary units. One pound equals sixteen ounces, and the pound is formally defined as exactly 0.45359237 kilograms. The imperial system traces its roots to ancient Roman and medieval English measurement standards. While most of the world has moved to metric, the United States continues to use pounds and ounces for everyday purposes including grocery shopping, body weight, and postal services. The United Kingdom occupies an interesting middle ground: it officially uses the metric system but culturally retains the stone (equal to fourteen pounds) for expressing body weight. If someone in Britain tells you they weigh ten stone, that means 140 pounds or about 63.5 kilograms.
Tons present a particularly confusing area because three different units share the name. The metric ton, also called a tonne, equals exactly 1,000 kilograms or approximately 2,204.6 pounds. The US ton, known as the short ton, equals 2,000 pounds or about 907.2 kilograms. The imperial ton, known as the long ton, equals 2,240 pounds or about 1,016 kilograms. The long ton was historically used in British shipping and trade, while the short ton became standard in North American commerce. When reading specifications for vehicles, shipping containers, or industrial materials, it is essential to know which type of ton is being referenced, as the difference between a short ton and a metric ton exceeds 200 pounds.
At the smaller end of the scale, milligrams and grams are indispensable in fields such as medicine, chemistry, and jewelry. Pharmaceutical dosages are almost always measured in milligrams, and even a small error in conversion can have significant health consequences. One gram contains one thousand milligrams, and one kilogram contains one million milligrams. Scientists working in laboratories routinely handle measurements in the microgram range, but for most practical everyday purposes, milligrams represent the finest granularity people encounter.
Understanding the distinction between mass and weight is also valuable. In physics, mass is a measure of how much matter an object contains and remains constant regardless of location. Weight, on the other hand, is the gravitational force acting on that mass and varies depending on the strength of the gravitational field. An astronaut with a mass of 70 kilograms would weigh about 686 newtons on Earth but only about 114 newtons on the Moon. In everyday language, however, we use the terms interchangeably because gravitational acceleration is essentially constant across Earth's surface.
Choosing the right unit depends entirely on context. For international trade and science, kilograms and metric tons are the standard. For daily life in the United States, pounds and ounces remain dominant. For body weight in the United Kingdom, stones and pounds persist. For precious metals, the troy ounce (approximately 31.1 grams, heavier than a standard ounce) is the industry standard. This converter supports all major units, letting you switch between metric, imperial, and specialized systems effortlessly to ensure you always have the precise figure you need.
Common Scenarios
Jewelry Appraiser
A gemologist weighing diamonds in carats needs to convert to grams for insurance documentation and to troy ounces for gold setting valuations. Precision down to the hundredth of a gram directly affects appraisal values worth thousands of dollars.
International Shipper
A logistics coordinator calculates freight costs where carriers quote in kilograms but the warehouse records are in pounds. Converting accurately ensures correct invoicing and prevents shipments from exceeding weight limits at customs checkpoints.
Fitness Enthusiast
A personal trainer following a European strength program listed in kilograms needs to load plates marked in pounds at an American gym. Quick conversion ensures the right training intensity without risking injury from accidentally overloading the bar.
Common Questions
What is the formula to convert kilograms to pounds?
To convert kilograms to pounds, multiply the kilogram value by 2.20462. The formula is: lb = kg × 2.20462. For example, 10 kg equals 22.0462 lb. This factor comes from the international definition of one pound being exactly 0.45359237 kilograms. To convert back from pounds to kilograms, divide the pound value by 2.20462 or multiply by 0.45359237.
What is the difference between metric and imperial weight systems?
The metric system is based on the gram and uses powers of ten for larger and smaller units: milligrams, grams, kilograms, and metric tons. The imperial system uses ounces, pounds, and stones with non-decimal relationships: 16 ounces in a pound and 14 pounds in a stone. The metric system is used by most of the world and by all scientists, while the imperial system persists primarily in the United States, the United Kingdom, and a few other countries for everyday measurements.
What is a troy ounce and how does it differ from a regular ounce?
A troy ounce is a unit of weight used exclusively for precious metals such as gold, silver, and platinum. It equals approximately 31.1035 grams. A standard ounce (called an avoirdupois ounce) equals approximately 28.3495 grams. This means a troy ounce is about 10 percent heavier than a regular ounce. When gold prices are quoted per ounce, they always refer to the troy ounce, not the avoirdupois ounce used at grocery stores.
Why is the stone unit still used in the United Kingdom?
The stone, equal to 14 pounds or about 6.35 kilograms, remains common in the United Kingdom and Ireland for expressing human body weight. This is primarily a matter of cultural tradition. Although the UK officially adopted the metric system for most purposes, colloquial usage of stones and pounds for body weight has persisted across generations. Medical professionals in the UK often record weight in both kilograms and stones to accommodate patient preferences.
What is the difference between a US ton, Imperial ton, and metric ton?
A US ton (short ton) equals 2,000 pounds or approximately 907.185 kilograms. An Imperial ton (long ton) equals 2,240 pounds or approximately 1,016.047 kilograms. A metric ton (tonne) equals exactly 1,000 kilograms or approximately 2,204.62 pounds. The short ton is standard in North American commerce, the long ton was historically used in British shipping, and the metric ton is the international standard used in global trade and science.
How many grams are in one pound?
One avoirdupois pound is defined as exactly 453.59237 grams. This is the international standard used since 1959 when the United States, United Kingdom, and other English-speaking countries agreed on a common definition. This means one pound is slightly less than half a kilogram, and one kilogram equals approximately 2.20462 pounds. For rough mental math, you can think of one kilogram as roughly two and a fifth pounds.
Is mass the same as weight?
In physics, mass and weight are different concepts. Mass measures the amount of matter in an object and is measured in kilograms. Weight measures the gravitational force on that mass and is measured in newtons. An object with a mass of 1 kilogram weighs about 9.81 newtons on Earth but only about 1.62 newtons on the Moon. However, in everyday life and for this converter, the terms are used interchangeably because Earth's gravitational field is effectively constant at the surface.
Common Weight Conversions Reference
Weight conversions come up constantly in cooking, fitness, shipping, and science. Having a quick reference for the most frequently needed conversions saves time and prevents errors. The tables below organize conversions by practical context so you can find exactly what you need for your specific situation.
Cooking and Baking
| US Measurement | Metric Equivalent | Typical Ingredient |
|---|---|---|
| 1 ounce (oz) | 28.35 g | Cheese slice, chocolate square, small spice portion |
| 4 ounces (1/4 lb) | 113.4 g | Stick of butter, single burger patty |
| 1 pound (lb) | 453.6 g | Ground meat package, bag of sugar, two cups of flour |
| 2.2 pounds | 1 kg | Large bag of rice, family chicken breast pack |
Fitness and Body Weight
| Pounds (lb) | Kilograms (kg) | Context |
|---|---|---|
| 5 lb | 2.27 kg | Light dumbbell, typical weight loss goal per month |
| 45 lb | 20.4 kg | Standard Olympic barbell plate, gym weight standard |
| 150 lb | 68.0 kg | Average adult body weight, medical dosage reference |
| 225 lb | 102.1 kg | Common bench press milestone, two plates per side |
Shipping and Logistics
| Unit | Equivalent | Used For |
|---|---|---|
| 1 short ton (US) | 2,000 lb / 907.2 kg | US freight, trucking weight limits, gravel and sand |
| 1 metric tonne | 2,204.6 lb / 1,000 kg | International shipping, cargo containers, bulk commodities |
| 1 long ton (UK) | 2,240 lb / 1,016 kg | British naval tradition, some UK freight contexts |
| 1 stone | 14 lb / 6.35 kg | Body weight in the UK and Ireland, horse racing |
The distinction between short tons, metric tonnes, and long tons is a common source of expensive confusion in international logistics. Always confirm which "ton" a trading partner means before finalizing contracts. Use the weight converter tool above for precise, instant conversions across all weight units.