How to Use This Tool

Weight converter

Type a value into any field and the converter calculates the rest. It handles pounds, kilograms, ounces, grams, stones, and metric tons. All conversions use the internationally agreed definitions: one pound equals exactly 0.45359237 kilograms, one kilogram equals 2.20462 pounds, and one ounce equals 28.3495 grams.

Common weight conversions

Weight conversion formulas

Pounds to kilograms

kg = lb x 0.45359237

Example: 150 lb x 0.453592 = 68.04 kg

Kilograms to pounds

lb = kg x 2.20462

Example: 75 kg x 2.20462 = 165.35 lb

Ounces to grams

g = oz x 28.3495

Example: 8 oz x 28.3495 = 226.8 g

Grams to ounces

oz = g x 0.035274

Example: 500 g x 0.035274 = 17.64 oz

Stones to pounds

lb = stones x 14

Example: 11 stone x 14 = 154 lb

When you need weight conversions

Body weight

The US uses pounds, most of the world uses kilograms, and the UK often uses stones. A person weighing 165 pounds is 74.8 kg or 11 stone 11 pounds. Medical records, gym equipment, and fitness apps vary by region, so converting is routine for anyone tracking weight across different systems.

Cooking and baking

American recipes use ounces and cups. European and Australian recipes use grams. A recipe calling for 8 ounces of flour is asking for 227 grams. Getting this wrong by even 10-15% can change the texture of baked goods, especially bread and pastry where ratios matter.

Shipping and postage

USPS and FedEx price domestic shipments in pounds and ounces. International carriers and customs forms use kilograms. A package weighing 2 pounds 6 ounces is 1.08 kg. Rounding up to 1.1 kg on a customs declaration is fine, but underreporting can cause delays at the border.

Grocery shopping

US stores price meat and produce per pound. Imported products and many health-food labels use grams or kilograms. A 500 g package of pasta is 1.1 pounds. Knowing that 100 grams is about 3.5 ounces helps compare nutrition labels across different packaging standards.

Fitness and supplements

Weightlifting plates come in both pound and kilogram denominations. An Olympic barbell weighs 20 kg (44.1 lb), and standard plates are either 45 lb or 20 kg. Protein powder scoops are measured in grams. A 30 g scoop is just over 1 ounce.

Common items by weight

Tips for accurate weight conversions

• For pounds to kilograms, a quick estimate is to divide by 2.2. It is not exact, but close enough for everyday use. 180 lb / 2.2 = 81.8 kg (precise answer: 81.6 kg).
• Remember that “weight” in everyday language usually means mass. Scientifically, weight is a force measured in newtons, but for cooking, shipping, and body weight, pounds and kilograms both refer to mass.
• Do not confuse fluid ounces with weight ounces. A fluid ounce measures volume, not weight. 8 fluid ounces of water happens to weigh about 8.3 ounces, but 8 fluid ounces of honey weighs about 12 ounces.
• When converting stones to kilograms, multiply by 6.35. A person weighing 12 stone is 76.2 kg or about 168 pounds.

Mass, weight, and the units behind them

The kilogram is the base unit of mass in the metric system, redefined in 2019 using the Planck constant rather than a physical artifact. The pound is defined as exactly 0.45359237 kilograms. The ounce is 1/16 of a pound. The stone, still used informally in the UK and Ireland for body weight, is 14 pounds.

The metric system makes scaling simple: 1000 grams = 1 kilogram, 1000 kilograms = 1 metric ton. The imperial system requires memorizing: 16 ounces = 1 pound, 14 pounds = 1 stone, 2000 pounds = 1 short ton (US), 2240 pounds = 1 long ton (UK).

Frequently asked questions

How many pounds is 1 kilogram?

1 kg = 2.20462 pounds.

How many kilograms is 1 pound?

1 lb = 0.453592 kg.

How many grams is 1 ounce?

1 oz = 28.3495 grams.

How many ounces are in a pound?

There are exactly 16 ounces in 1 pound.

What is a stone in pounds?

1 stone = 14 pounds. The stone is used mainly in the UK and Ireland for body weight.

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

A metric ton (tonne) is 1000 kg (2204.6 lb). A US short ton is 2000 lb (907.2 kg). A UK long ton is 2240 lb (1016 kg). The metric ton is about 10% heavier than a US short ton.

How do I convert body weight from pounds to kg?

Divide your weight in pounds by 2.205. A 180-pound person weighs 81.6 kg.

Is a kilogram heavier than a pound?

Yes. One kilogram equals about 2.2 pounds, so a kilogram is more than twice as heavy as a pound.

Related conversion tools

• Pounds to Kilograms Converter
• Ounces to Grams Converter
• Inches to Centimeters Converter
• Feet to Meters Converter

Measurement guides

• How Big Is X Inches? A Visual Size Guide From 1 to 16 Inches
• Inches Explained: Conversion Chart, Tools, and Real-World Examples

Formula & Explanation

All weight conversions use the international avoirdupois system. The pound is defined as exactly 0.45359237 kilograms by an international agreement in effect since 1959.