Weight Converter - kg, lb, oz, g, stone & tonnes

Weight conversion comes up in situations ranging from the mundane to the mission-critical.

You might need to convert kilograms to pounds for an airline baggage limit, grams to ounces for a baking recipe, or metric tons to short tons for a shipping invoice. Whatever the scenario, getting the conversion right matters, and doing it in your head with approximate factors invites errors.

This weight converter handles conversions between all commonly used weight and mass units, including milligrams, grams, kilograms, metric tons, ounces, pounds, stones, short tons (US), and long tons (UK). It also supports troy ounces used in precious metals trading. Every conversion uses exact or internationally standardized factors, so the results are reliable for both casual use and professional applications.

The tool updates results in real time as you type, supports decimal input for fractional values, and displays enough significant digits for any practical purpose. Whether you are a home cook scaling a European recipe, a fitness enthusiast tracking macros in grams, or a logistics professional calculating shipping weights, this converter gives you the right number every time.

Understanding Weight vs Mass

Before diving into conversions, it helps to understand a subtle but important distinction. Technically, weight and mass are different things. Mass is a measure of how much matter an object contains, measured in kilograms in the SI system. Weight is the force exerted on that mass by gravity, measured in Newtons.

In everyday life, this distinction is almost irrelevant. On Earth’s surface, a one-kilogram mass weighs approximately 9.81 Newtons, and we casually say it "weighs one kilogram." The conversion factors used in this tool assume standard Earth gravity, which is correct for any practical terrestrial application. The distinction only matters in physics problems or when calculating weights on other celestial bodies.

What we colloquially call "weight units" are technically a mix of mass units (grams, kilograms, metric tons) and force units historically used as weight (pounds, ounces). Again, on Earth’s surface the practical difference is negligible, and this converter treats them interchangeably as everyone does in daily use.

Kilograms to Pounds

The kilogram-to-pound conversion is the most commonly searched weight conversion, used for everything from body weight to luggage limits to grocery shopping.

The exact relationship: 1 kilogram = 2.20462262 pounds. For quick mental math, multiply kilograms by 2.2. To convert pounds to kilograms, divide by 2.2 (or more precisely, multiply by 0.45359237).

Body weight reference points:

50 kg = 110.2 lbs
60 kg = 132.3 lbs
70 kg = 154.3 lbs
80 kg = 176.4 lbs
90 kg = 198.4 lbs
100 kg = 220.5 lbs

Airline baggage limits are typically set in kilograms for international flights. A common checked bag limit of 23 kg equals about 50.7 pounds. A 32 kg limit (business class on many carriers) is about 70.5 pounds. A 7 kg carry-on limit is about 15.4 pounds. Exceeding these limits by even a fraction can result in steep excess baggage fees, making accurate conversion worthwhile.

Grocery shopping across systems can be confusing. Recipes and food labels from metric countries list ingredients in grams or kilograms. When a recipe calls for 500 grams of chicken breast, that is 1.1 pounds. A 2-pound package of ground beef is 907 grams.

Grams to Ounces

Gram-to-ounce conversion is essential for cooking, baking, nutritional tracking, and postal shipping.

The exact relationship: 1 ounce (avoirdupois) = 28.349523125 grams. To convert grams to ounces, divide by 28.35. To convert ounces to grams, multiply by 28.35.

Cooking and baking conversions between grams and ounces are among the most common uses. Professional bakers worldwide measure ingredients by weight in grams because it is more accurate than volume measurements. A cup of flour can vary from 120 to 150 grams depending on how it is scooped, but 150 grams is always 150 grams regardless of technique.

Common baking ingredient weights:

1 oz butter = 28 g
4 oz chocolate = 113 g
8 oz cream cheese = 227 g
16 oz (1 lb) sugar = 454 g

Nutritional labels in the US list serving sizes in grams, while the UK and EU also use grams. A 28-gram serving of chips is about 1 ounce. A 100-gram reference serving (used on EU labels) is about 3.5 ounces.

For ingredient-specific conversions that account for density differences (cups to grams), use the Cooking Measurement Converter.

Stones to Pounds and Kilograms

The stone is a unit of weight still widely used in the United Kingdom and Ireland for expressing body weight. It is not commonly used in the US or in metric countries, which can cause confusion in international contexts.

The exact relationship: 1 stone = 14 pounds = 6.35029318 kilograms.

Reference points for body weight:

8 stone = 112 lbs = 50.8 kg
10 stone = 140 lbs = 63.5 kg
12 stone = 168 lbs = 76.2 kg
14 stone = 196 lbs = 88.9 kg
16 stone = 224 lbs = 101.6 kg

If someone in the UK tells you they weigh "11 stone 7," that means 11 stones and 7 pounds, which equals 161 pounds or 73 kilograms.

Metric Tons, Short Tons, and Long Tons

Three different units all use the word "ton," and confusing them can be extremely costly in industrial and shipping contexts.

Metric Ton (Tonne). One metric ton equals exactly 1,000 kilograms or approximately 2,204.6 pounds. This is the standard in international trade, science, and most countries worldwide. It is abbreviated as "t" or "MT."

Short Ton (US Ton). One short ton equals exactly 2,000 pounds or approximately 907.2 kilograms. This is the standard ton in the United States. When Americans say "ton" without qualification, they typically mean the short ton.

Long Ton (Imperial Ton). One long ton equals exactly 2,240 pounds or approximately 1,016 kilograms. This unit was historically used in the United Kingdom and is still encountered in some British contexts, particularly in naval terminology (displacement tonnage of ships).

The differences are significant. A cargo container loaded to 20 metric tons weighs 44,092 pounds. If someone interprets that as 20 short tons (40,000 pounds), the container is over its expected weight by more than 2 tons. In shipping and logistics, always clarify which "ton" is being referenced.

Troy Ounces for Precious Metals

If you trade gold, silver, platinum, or palladium, you need to know about troy ounces. The troy ounce is different from the standard (avoirdupois) ounce used for everyday weight.

The exact relationship: 1 troy ounce = 31.1035 grams. One standard ounce = 28.3495 grams. A troy ounce is about 10% heavier than a standard ounce.

When gold is quoted at a price per ounce, that price refers to the troy ounce. One troy ounce of gold is 31.1 grams, not 28.3 grams. Confusing the two would lead to a roughly 10% error in your price calculation.

Troy weight system measurements:

1 troy ounce = 31.1035 grams
1 troy pound = 12 troy ounces = 373.24 grams
Note: a troy pound has 12 ounces, not 16 like a standard pound

Milligrams and Micrograms

At the small end of the weight scale, milligrams and micrograms are used in medicine, chemistry, nutrition, and laboratory work.

Key relationships:

1 gram = 1,000 milligrams (mg)
1 milligram = 1,000 micrograms (mcg or ug)
1 gram = 1,000,000 micrograms

Medication dosing is almost always in milligrams. A standard ibuprofen tablet is 200 mg. A typical vitamin D supplement is 1,000 IU, which equals 25 micrograms. Getting these conversions wrong in medical contexts can have serious consequences. Always verify dosage units carefully.

Nutritional supplements list amounts in milligrams (mg) or micrograms (mcg). The recommended daily intake of vitamin C is 65 to 90 mg. The recommended daily intake of vitamin B12 is 2.4 mcg. Note that "mcg" and "ug" both mean micrograms, and some labels use one while others use the other.

Practical Weight Conversion Tips

Memorize a few anchor points. You do not need exact factors for everyday estimates. Knowing that 1 kg is about 2.2 lbs, 1 oz is about 28 g, and 1 stone is 14 lbs covers most situations. For precise work, use this converter.

Check unit abbreviations carefully. In technical documents, "oz" usually means avoirdupois ounces, "oz t" means troy ounces, and "fl oz" means fluid ounces (a volume unit, not a weight unit). Confusing fluid ounces with weight ounces is a common mistake, especially in cooking.

Account for container weight. When converting weights for shipping or cooking, make sure you are working with net weight (contents only) rather than gross weight (contents plus container). A bag of flour listed as "2 kg" refers to the flour, not the flour plus the bag.

Understand significant figures. If you weigh something on a kitchen scale that reads to the nearest gram, reporting the conversion to six decimal places is false precision. Match the precision of your converted result to the precision of your original measurement.

For comprehensive unit conversions across all categories, visit the Unit Converter.

Frequently Asked Questions

How many pounds are in a kilogram?

One kilogram equals approximately 2.20462 pounds. For quick mental math, multiply kilograms by 2.2. To convert pounds to kilograms, divide by 2.2. For example, 75 kg equals about 165.3 pounds.

What is the difference between a troy ounce and a regular ounce?

A troy ounce equals 31.1035 grams, while a regular (avoirdupois) ounce equals 28.3495 grams. Troy ounces are about 10% heavier and are used exclusively for precious metals like gold and silver. When gold prices are quoted per ounce, they refer to troy ounces.

How many grams are in an ounce?

One avoirdupois ounce equals approximately 28.3495 grams. For a quick estimate, round to 28 grams. To convert grams to ounces, divide by 28.35.

What is a stone in pounds?

One stone equals exactly 14 pounds or approximately 6.35 kilograms. The stone is commonly used for body weight in the United Kingdom and Ireland. A person weighing 10 stone 7 weighs 147 pounds or about 66.7 kilograms.

What is the difference between a metric ton and a US ton?

A metric ton (tonne) equals 1,000 kilograms or about 2,204.6 pounds. A US short ton equals 2,000 pounds or about 907.2 kilograms. The metric ton is approximately 10% heavier. Always clarify which ton is being used in shipping and trade contexts.

How do I convert body weight from kg to lbs?

Multiply your weight in kilograms by 2.205 to get pounds. For example, 70 kg x 2.205 = 154.3 lbs. For the reverse, divide pounds by 2.205. A 180-pound person weighs about 81.6 kg.

How many milligrams are in a gram?

One gram equals exactly 1,000 milligrams. One milligram equals 0.001 grams. This conversion is critical for medication dosing and nutritional label reading. For example, 500 mg is the same as 0.5 grams.

What does net weight vs gross weight mean?

Net weight is the weight of the contents only, excluding packaging. Gross weight includes both the contents and the packaging. When converting weights for recipes or shipping, make sure you are using the correct figure. Food labels typically list net weight.

Conversion factors based on NIST and BIPM international standards. Data accurate as of: March 2026