Weight Calculator
Convert weight units between lb, kg, stone, oz, and metric tons.
Weight Calculator
Convert weight units between lb, kg, stone, oz, and metric tons.
Unit Conversion
ℹ️ All units normalised to a common base before converting to ensure accuracy
Disclaimer
Results provided by this calculator are for informational and educational purposes only. They are based on the values you enter and standard formulas, and should not be considered financial, medical, legal, or professional advice. Always consult a qualified professional before making important decisions based on these results. Roughtools makes no warranties regarding the accuracy or completeness of these calculations for your specific situation.
Frequently Asked Questions
Pro Tips
Always double-check your unit conversion direction — dividing when you should multiply (or vice versa) produces a result off by the conversion factor squared.
For temperature conversions, remember the formulas differ: Celsius to Fahrenheit = (C × 9/5) + 32. Fahrenheit to Celsius = (F − 32) × 5/9. Kelvin = Celsius + 273.15.
Imperial units have multiple definitions (fluid ounce vs weight ounce, US vs UK gallon). Always confirm which system applies — especially for cooking or scientific work.
Significant figures matter in scientific conversions. If your input has 2 significant figures, don't report 6 decimal places of precision — it implies false accuracy.
When to Use This Calculator
Convert between metric and imperial units for temperature, distances, weights, and speeds when travelling abroad.
Convert between US and metric measurements for international recipes or ingredient scaling.
Convert units for scientific calculations where SI units are required.
Convert between measurement systems when working with international suppliers or standards.
Convert units to compare product sizes and prices across different packaging formats.
About the Weight Calculator
This weight calculator converts between all common weight units — pounds (lb), kilograms (kg), stones (st), ounces (oz), grams (g), and metric tons — with instant results in both directions. Enter any weight in any unit to see all equivalents simultaneously. Includes a body weight section for converting personal weight for medical forms, travel, and international fitness apps that use different unit standards.
How to Use the Weight Calculator
- 1
Enter your weight value in the input field.
- 2
Select the unit you're converting from: lb, kg, stone, oz, g, or tonnes.
- 3
See instant conversions to all other weight units.
- 4
For body weight: enter your weight in pounds to see kg for medical forms, or kg to see pounds for US use.
- 5
Use the stone+pounds split display for UK-style weight entry.
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