⚖️ Weight Converter
Switch between pounds, kilograms, grams, ounces, stones, milligrams, and metric tonnes.
Enter a value above to see the result
Common Weight Conversions
| Input | Unit | Result | Unit |
|---|---|---|---|
| 1 | Pound | 0.45359237 | Kilogram |
| 1 | Kilogram | 2.2046226 | Pound |
| 1 | Ounce | 28.349523 | Gram |
| 100 | Gram | 3.5273962 | Ounce |
| 1 | Stone | 6.3502932 | Kilogram |
| 70 | Kilogram | 154.32358 | Pound |
Popular Conversions
Health & Fitness Tools
About Weight Conversions
Weight — more precisely, mass — is measured in everyday contexts using kilograms, grams, pounds, and ounces. The metric system, anchored to the kilogram, is the international standard and is used in science, medicine, and most countries worldwide. In 2019, the kilogram was redefined in terms of the Planck constant, making it one of the most precisely defined units in history.
The imperial system uses pounds (lb) and ounces (oz), with 16 ounces to the pound. The stone (14 pounds) is still used informally in the UK and Ireland for describing body weight. Metric tonnes (1,000 kg) are used for large quantities in shipping and international trade, while milligrams appear in pharmaceutical dosing.
Technically, weight and mass are not the same thing. Mass measures the amount of matter in an object and is constant regardless of location. Weight is the gravitational force acting on that mass — you would weigh less on the Moon but your mass would be unchanged. In everyday usage the terms are used interchangeably, which is acceptable for most practical purposes.
Frequently Asked Questions
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. Conversely, one pound equals approximately 0.453592 kilograms. A quick rough estimate: multiply kilograms by 2.2 to get pounds.
How many ounces are in a pound?
There are exactly 16 avoirdupois ounces in one pound. This is the standard system for everyday goods in the United States. Note that troy ounces — used for precious metals like gold and silver — are slightly heavier (1 troy ounce ≈ 31.1 grams vs. 28.35 grams for avoirdupois).
What is a stone in pounds and kilograms?
One stone equals exactly 14 pounds, or approximately 6.35 kilograms. The stone remains in informal use in the UK and Ireland for expressing body weight. It is not recognized by the SI system.
How many grams are in an ounce?
One avoirdupois ounce equals approximately 28.3495 grams. For cooking, 28 grams is often used as a quick approximation. For precious metals using the troy system, one troy ounce equals approximately 31.1035 grams.
Is weight the same as mass?
In everyday language they are used interchangeably, but in physics they differ. Mass is the amount of matter in an object (constant everywhere) and is measured in kilograms. Weight is the gravitational force on that mass, measured in newtons. On the Moon, your mass stays the same but you weigh about one-sixth of what you do on Earth.
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Related Guides
Kilograms vs Pounds Explained
Kilograms and pounds both measure mass but belong to different systems. Learn the key differences, which countries use each unit, and the exact conversion factor.
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How to Convert Kilograms to Pounds
To convert kilograms to pounds, multiply by 2.20462. Learn the formula, a mental shortcut, a full reference table, and worked examples for common weights.
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How to Convert Pounds to Kilograms
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Why Most Countries Use Kilograms
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Kilograms to Pounds Formula Explained
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Pounds to Kilograms Formula Explained
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Grams to Ounces Formula Explained
The exact formula for converting grams to ounces (divide by 28.3495 or multiply by 0.035274), with worked examples, a reference table, and the troy vs. avoirdupois ounce distinction.
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How to Convert Grams to Ounces
Step-by-step instructions for converting grams to ounces, with the formula, a mental shortcut, worked examples for cooking and nutrition, and a quick reference table.
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Ounces to Grams Formula Explained
The exact formula for converting ounces to grams (multiply by 28.3495), where the factor comes from, worked examples, and the important distinction between avoirdupois and troy ounces.
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How to Convert Ounces to Grams
Step-by-step guide to converting ounces to grams using the formula (×28.3495), a mental shortcut, worked examples for cooking and recipe adaptation, and a quick reference table.
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Stone to Pounds Formula Explained
The exact formula for converting stone to pounds (1 stone = 14 pounds exactly), with worked examples, a combined stone-and-pounds reference table, and context for UK body weight usage.
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How to Convert Stone to Pounds
Step-by-step guide to converting stone to pounds — covering whole stone values, combined 'X stone Y pounds' formats, and how to then convert to kilograms.
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Weight Conversion Guide: Kilograms, Pounds, Ounces, and More
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Kilograms vs Pounds: Understanding the Key Differences
Kilograms (kg) and pounds (lb) are the two most commonly compared weight units. Learn the exact conversion factor, where each is used, and why the world uses kilograms while the US uses pounds.
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What Is a Stone in Weight? Definition, History, and Conversions
A stone is a unit of body weight equal to exactly 14 pounds or 6.35 kilograms. Used primarily in the UK and Ireland for expressing body weight. Learn its history, how to convert it, and where it is still used.
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Metric vs Imperial Weight: A Complete Comparison
Metric weight units (kilograms, grams) vs imperial/US customary units (pounds, ounces). Understand which system is used where, the key conversion factors, and the history behind each system.
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Common Weight Units Explained: From Milligrams to Metric Tons
A complete reference for all common weight and mass units — milligrams, grams, kilograms, ounces, pounds, stone, and metric tons. Learn what each unit represents and when to use it.
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Reference Handbooks
Sources
Our Methodology
How we source and verify conversion factors.
Reference Library
Tables, charts, and authoritative reference data.
Reference Charts
Pounds to Kilograms Conversion Chart
Quick-reference chart converting pounds (lbs) to kilograms (kg). Covers 1–500 lb at common intervals with the exact conversion formula.
Kilograms to Pounds Conversion Chart
Quick-reference chart converting kilograms (kg) to pounds (lbs). Covers 1–250 kg at common intervals with the exact conversion formula.
Grams to Ounces Conversion Chart
Quick-reference chart converting grams (g) to ounces (oz). Covers 1 g to 1,000 g — essential for cooking, baking, food labels, and recipe adaptation.
Ounces to Grams Conversion Chart
Quick-reference chart converting ounces (oz) to grams (g). Covers ½ oz to 64 oz — ideal for cooking, food packaging, and converting US recipes to metric.
Stone to Pounds Conversion Chart
Reference chart converting stone (st) to pounds (lb) and kilograms (kg). Covers 6 stone to 25 stone — the full UK adult body weight range.
All Converters
All conversion results are provided for general informational purposes only. Our formulas use internationally recognized conversion factors; however, rounding may affect precision. Do not rely on these results for professional, medical, legal, or engineering decisions without independent verification. Read our full disclaimer.