Weight Converter

How to Use the Weight Converter

Enter a numeric value in the input field and select the unit you are converting from. All seven weight units update instantly, showing milligrams, grams, kilograms, tonnes, ounces, pounds, and stone. The converter uses grams as the internal base unit, ensuring consistent accuracy across all conversions.

This tool is ideal for cooking and baking (converting recipe measurements), fitness tracking (body weight in different systems), shipping and logistics (package weights), and scientific work requiring precise unit conversion.

Understanding Weight Units

The metric system organizes weight in powers of ten: 1,000 milligrams make a gram, 1,000 grams make a kilogram, and 1,000 kilograms make a metric tonne. The imperial/avoirdupois system uses different relationships: 16 ounces in a pound, and 14 pounds in a stone. The stone is primarily used in the United Kingdom and Ireland for measuring body weight.

Common Conversion Factors

The most frequently needed conversions are: 1 pound = 453.592 grams, 1 ounce = 28.3495 grams, 1 kilogram = 2.20462 pounds, 1 stone = 6,350.29 grams (14 pounds), and 1 tonne = 1,000 kilograms. For quick mental estimates: 1 kilogram is roughly 2.2 pounds, and 1 pound is roughly 454 grams.

Metric Tonnes vs. Other Tons

The metric tonne (1,000 kg) is the internationally standardized unit. The US short ton equals 2,000 pounds (907.185 kg), while the Imperial long ton equals 2,240 pounds (1,016.05 kg). This converter uses the metric tonne. When working with shipping or commodity weights, be sure to clarify which "ton" is being referenced.

Frequently Asked Questions

How many grams are in a pound?

One pound equals approximately 453.592 grams. This conversion is based on the international avoirdupois pound. To convert pounds to grams, multiply by 453.592. To convert grams to pounds, divide by 453.592.

How many pounds are in a stone?

One stone equals exactly 14 pounds. The stone is a traditional British unit of weight still commonly used in the UK and Ireland for expressing body weight. To convert stone to pounds, multiply by 14.

What is the difference between mass and weight?

Mass measures the amount of matter in an object and is constant regardless of location. Weight is the force of gravity acting on that mass and varies with gravitational field strength. On Earth's surface, a 1 kg mass weighs approximately 9.81 newtons. In everyday use, the terms are often used interchangeably.

How do I convert ounces to grams?

One ounce (avoirdupois) equals approximately 28.3495 grams. Multiply ounces by 28.3495 to get grams, or divide grams by 28.3495 to get ounces. Note that troy ounces, used for precious metals, are different: 1 troy ounce equals 31.1035 grams.

How many kilograms are in a metric tonne?

One metric tonne equals exactly 1,000 kilograms. The tonne (also spelled metric ton) is the standard large-weight unit in the metric system. It is slightly larger than a US short ton (907.185 kg) and slightly smaller than an Imperial long ton (1,016.05 kg).