# Weight Converter

Free online weight converter. Convert between milligrams, grams, kilograms, ounces, pounds, stone, and metric tons with exact conversion factors.

## What this calculates

Quickly convert between metric and imperial weight units. This tool supports milligrams, grams, kilograms, ounces, pounds, stone, and metric tons with precise conversion factors based on international standards.

## Inputs

- **Value** — min 0
- **From** — options: Milligrams (mg), Grams (g), Kilograms (kg), Ounces (oz), Pounds (lb), Stone (st), Metric Tons (t)
- **To** — options: Milligrams (mg), Grams (g), Kilograms (kg), Ounces (oz), Pounds (lb), Stone (st), Metric Tons (t)

## Outputs

- **Result** — The converted weight value.
- **Conversion** — formatted as text — Step-by-step conversion explanation.

## Details

Weight (or more precisely, mass) conversion is essential in cooking, science, shipping, fitness, and daily life. The metric system uses grams and kilograms, while the imperial system uses ounces, pounds, and stone.

Key Conversion Factors

- 1 pound (lb) = 453.59237 grams (exact, by definition)

- 1 ounce (oz) = 28.349523125 grams (exact)

- 1 stone = 14 pounds = 6,350.29318 grams

- 1 metric ton = 1,000 kilograms

- 1 kilogram = 2.20462 pounds (approximately)

All conversions use the exact avoirdupois definitions adopted internationally. The avoirdupois ounce and pound are the standard units used in everyday commerce in the US and UK.

## Frequently Asked Questions

**Q: How many pounds are in a kilogram?**

A: There are approximately 2.20462 pounds in one kilogram. The exact conversion is 1 kg = 1/0.45359237 lb. To convert kg to lbs, multiply by 2.20462. To convert lbs to kg, multiply by 0.45359237.

**Q: What is a stone and how does it relate to pounds?**

A: A stone is an imperial unit of weight equal to exactly 14 pounds (approximately 6.35 kg). It is primarily used in the UK and Ireland to express body weight. For example, a person weighing 154 lbs weighs 11 stone.

**Q: What is the difference between mass and weight?**

A: Mass is the amount of matter in an object, measured in kilograms or pounds-mass. Weight is the force exerted by gravity on that mass, measured in newtons. In everyday usage, 'weight' typically refers to mass. This converter handles mass conversions.

**Q: Are ounces and fluid ounces the same?**

A: No. Ounces (oz) measure weight/mass, while fluid ounces (fl oz) measure volume. One fluid ounce of water weighs approximately 1.043 oz (avoirdupois). This converter handles weight ounces only; use the volume converter for fluid ounces.

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Source: https://vastcalc.com/calculators/conversion/weight-converter
Category: Conversion
Last updated: 2026-04-21