Weight Converter
Convert between kilograms, pounds, grams, ounces, stones, tons and more. Real-time conversion, no signup, works entirely in your browser.
Convert Weight
What does this Weight Converter do?
This free online weight converter converts between any two units of mass or weight instantly. Whether you're cooking, shipping a package, tracking fitness goals, or doing science homework, this tool gives you accurate results in real time.
It supports both the metric system (milligrams, grams, kilograms, metric tons, micrograms) and the imperial/US customary system (ounces, pounds, stones, US tons, UK tons). All conversions use internationally recognized, exact conversion factors.
Everything runs locally in your browser. No server, no signup, no tracking. Your measurements never leave your device.
How to use the Weight Converter
- Enter a value: Type the number you want to convert in the "From" field.
- Pick your source unit: Select the unit you're converting from (e.g., kilograms, pounds, grams).
- Pick your target unit: Select the unit you want to convert to (e.g., pounds, ounces, stones).
- See the result instantly: The converted value appears in the "To" field and in the result box below — no button press needed.
- Use quick conversions: Click any of the preset buttons below to instantly convert common values like "1 kg → lb" or "1 g → oz".
- Swap units: Click the swap button to reverse the conversion direction in one click.
- Copy the result: Use the "Copy Result" button to grab the converted value for use elsewhere.
Why use this Weight Converter?
Real-time conversion
As you type, the result updates instantly. No button press needed, no waiting.
10 units supported
Milligrams, grams, kilograms, metric tons, micrograms, ounces, pounds, stones, US tons, and UK tons.
One-click swap
Swap the from and to units instantly with a single click. No need to re-enter the value.
Copy & reset
Copy the result to your clipboard or reset the converter to its default state with one click.
100% private
Everything runs in your browser. No server, no logs, no tracking. Your data never leaves your device.
Works offline
Once the page loads, the converter works without an internet connection. Perfect for travel or remote areas.
Weight conversion factors
Here are the exact conversion factors used by this converter. All values are based on international standards.
| From | To | Multiply by | Example |
|---|---|---|---|
| Kilograms (kg) | Pounds (lb) | 2.20462 | 10 kg = 22.0462 lb |
| Pounds (lb) | Kilograms (kg) | 0.453592 | 10 lb = 4.53592 kg |
| Grams (g) | Ounces (oz) | 0.035274 | 100 g = 3.5274 oz |
| Ounces (oz) | Grams (g) | 28.3495 | 10 oz = 283.495 g |
| Stones (st) | Kilograms (kg) | 6.35029 | 10 st = 63.5029 kg |
| Metric Tons (t) | Pounds (lb) | 2204.62 | 2 t = 4409.24 lb |
| US Tons (short) | Kilograms (kg) | 907.185 | 1 US ton = 907.185 kg |
| UK Tons (long) | Kilograms (kg) | 1016.05 | 1 UK ton = 1016.05 kg |
| Milligrams (mg) | Grams (g) | 0.001 | 1000 mg = 1 g |
| Micrograms (µg) | Milligrams (mg) | 0.001 | 1000 µg = 1 mg |
Metric vs. imperial: what's the difference?
The world uses two main systems of measurement for weight and mass: the metric system and the imperial (or US customary) system. Understanding the difference helps you choose the right unit for the job.
The metric system
Used by almost every country in the world (the US is a notable exception). The metric system is based on powers of 10, which makes conversions between units simple — just move the decimal point. The base unit is the kilogram.
- Milligram (mg): 1/1,000,000 of a kilogram. Used for medication and tiny measurements.
- Gram (g): 1/1,000 of a kilogram. Common for cooking and food labels.
- Kilogram (kg): The base unit. Used for body weight, groceries, and shipping.
- Metric Ton (t): 1,000 kilograms. Used for vehicles, cargo, and industrial measurements.
- Microgram (µg): 1/1,000,000,000 of a kilogram. Used in pharmacology and chemistry.
The imperial / US customary system
Used primarily in the United States, and informally in the UK and a few other countries. The relationships between units are less uniform, so conversions require specific factors.
- Ounce (oz): 1/16 of a pound. Used for small measurements and food portions.
- Pound (lb): 16 ounces. Common for body weight and larger food items.
- Stone (st): 14 pounds. Commonly used in the UK and Ireland for body weight.
- US Ton (short ton): 2,000 pounds. Used in the US for industrial and shipping weights.
- UK Ton (long ton): 2,240 pounds. Historically used in the UK.
The difference between mass and weight
Technically, mass is the amount of matter in an object (measured in kg, g, lb), while weight is the force of gravity on that mass (measured in newtons). In everyday language, "weight" and "mass" are used interchangeably, and this converter follows that convention.
Common weight conversion use cases
Cooking and baking
- Converting recipe measurements between grams and ounces
- Scaling recipes up or down while keeping proportions accurate
- Converting ingredient weights for international recipes
Fitness and health
- Converting body weight between kilograms and pounds
- Tracking weight loss or muscle gain in your preferred unit
- Converting weights for UK stone measurements
Shipping and logistics
- Calculating shipping costs based on package weight
- Converting between metric and imperial tons for freight
- Preparing customs declarations with correct weight units
Science and academics
- Chemistry lab measurements in milligrams and micrograms
- Physics problems involving mass and weight
- Comparing data across scientific papers using different units