Weight (Mass) Conversion Calculator
Convert among different units of weight or mass. Enter a value and select the units to convert from and to.
| Unit | Value | Symbol |
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What Is a Weight (Mass) Conversion Calculator?
A Weight (Mass) Conversion Calculator is a simple but powerful online tool that helps you convert between different units of weight such as kilograms, grams, pounds, and ounces. Whether you’re converting for science, engineering, fitness, or everyday use, this calculator saves time and ensures accuracy.
It supports both metric (gram, kilogram, tonne) and imperial (ounce, pound, stone, ton) systems, making it ideal for global users.
How to Convert Units of Weight (Mass)
Converting between weight units is straightforward when you know the conversion factor — the number that links one unit to another.
The general formula is:
S × C = E
Where:
- S = starting value
- C = conversion factor
- E = end converted value
For example:
If you want to convert 5 kilograms to grams, multiply by 1000.
5 × 1000 = 5000 g
To go in the opposite direction — from grams to kilograms — simply divide:
5000 ÷ 1000 = 5 kg
This rule works for any weight unit, whether you’re converting micrograms, pounds, or tons.
Formula for Weight Conversion Between Any Units
You can easily convert from any unit A to another unit B using this formula:
Value in B = (Value in A × Factor of A) ÷ Factor of B
Example: Convert 1 kilogram to pounds.
- Factor of kilogram = 1000 (grams)
- Factor of pound = 453.59237 (grams)
So,
1 × 1000 ÷ 453.59237 = 2.204622 lb
That means 1 kg = 2.204622 lb.
You can try a similar calculation for pounds to kilograms using our pounds to kilograms converter for quick and accurate results.
Common Weight (Mass) Conversion Factors
Here’s a table showing conversion factors for major weight units — these values represent how many grams are in one unit:
| Unit | Symbol | 1 Unit = (g) |
|---|---|---|
| Carat (metric) | ct | 0.2 |
| Dram (avdp) | dr | 1.771845195 |
| Grain (troy) | gr | 0.06479891 |
| Gram | g | 1 |
| Kilogram | kg | 1000 |
| Milligram | mg | 0.001 |
| Ounce (avdp) | oz | 28.34952313 |
| Pound (avdp) | lb | 453.59237 |
| Stone | st | 6350.29318 |
| Ton (short) | sh tn | 907184.74 |
| Tonne (metric ton) | t | 1000000 |
Each unit represents a different system of measurement. For instance, the avoirdupois system is used for everyday items, while troy units are used for precious metals like gold and silver.
Examples of Weight Conversion
1. Kilograms to Pounds
Formula: kg × 2.204622 = lb
Example: 10 kg × 2.204622 = 22.04622 lb
2. Pounds to Kilograms
Formula: lb ÷ 2.204622 = kg
Example: 50 lb ÷ 2.204622 = 22.6796 kg
For automatic calculation, you can use our dedicated kilograms to pounds calculator.
3. Grams to Ounces
Formula: g ÷ 28.34952313 = oz
Example: 500 g ÷ 28.34952313 = 17.637 oz
4. Ounces to Grams
Formula: oz × 28.34952313 = g
Example: 10 oz × 28.34952313 = 283.495 g
Metric vs Imperial Units of Weight
Weight (or mass) measurement systems fall mainly into two categories:
1. Metric System (SI Units)
- Common units: milligram (mg), gram (g), kilogram (kg), tonne (t).
- Used in most countries worldwide.
- Based on powers of ten — easy for conversions.
2. Imperial System (Avoirdupois)
- Common units: ounce (oz), pound (lb), stone (st), ton (tn).
- Used mainly in the United States and a few other regions.
- Not based on powers of ten, so conversions can be trickier.
If you frequently convert between metric and imperial units, try the metric unit conversion calculator for faster results.
Weight Conversion Tips
- To convert smaller to larger units, divide.
Example: grams → kilograms. - To convert larger to smaller units, multiply.
Example: kilograms → grams. - Always keep an eye on decimal accuracy, especially in scientific calculations.
- Remember that mass and weight are closely related but not identical — mass measures the amount of matter, while weight measures gravitational force.
Real-World Applications
1. Science and Engineering:
Converting between units like grams, kilograms, and newtons is crucial for physical calculations. For instance, you can use the force conversion calculator to relate weight and force.
2. Health and Fitness:
Body weight conversions are common for diet tracking or gym measurements, especially when converting between pounds and kilograms.
3. Commerce and Industry:
Businesses trading goods internationally must convert product weights accurately to comply with shipping and customs requirements.
4. Education:
Students in physics or chemistry often deal with different measurement systems for experiments and equations.
Why Use the Weight (Mass) Conversion Calculator?
Using the Weight (Mass) Conversion Calculator eliminates manual calculation errors and saves time. It’s:
- Accurate – Built using verified conversion constants.
- Fast – Converts instantly between dozens of units.
- Comprehensive – Covers both metric and imperial systems.
- User-friendly – Just enter your value and select your units.
This tool is part of the complete unit conversion calculators collection, where you can also convert temperature, distance, speed, and volume units.
Key Takeaways
- The Weight (Mass) Conversion Calculator simplifies all types of weight conversions.
- Always use the formula S × C = E to calculate conversions manually.
- Know your conversion factors — especially for kg, lb, oz, and g.
- Use online calculators for quick, accurate, and error-free results.
With this tool, anyone can confidently handle conversions — whether comparing recipes, calculating shipping costs, or performing scientific analysis.