Science & Lab Tools
Weight Calculator
Convert weight between different units with precision. Supports kilograms, pounds, stones, ounces, and more.
Enter a weight value and select units to see the conversion result
Related to Weight Calculator
The Weight Calculator performs precise conversions between different weight units using standardized conversion factors. The calculator uses a two-step conversion process: first converting the input weight to kilograms (the SI base unit for mass), then converting from kilograms to the desired output unit. This approach ensures accuracy and consistency across all unit conversions.
Common Conversion Factors
• 1 kilogram (kg) = 1000 grams (g)
• 1 gram (g) = 1000 milligrams (mg)
• 1 pound (lb) = 453.59237 grams
• 1 ounce (oz) = 28.349523125 grams
• 1 stone (st) = 6.35029318 kilograms
• 1 US ton = 907.18474 kilograms
Conversion Process
The calculator follows these steps:
1. Converts the input value to kilograms using the appropriate conversion factor
2. Converts the kilogram value to the target unit using its conversion factor
3. Displays the result with appropriate precision
The calculator displays the conversion result with six decimal places to ensure precision for both large and small measurements. The result shows the original value and unit, followed by the converted value and unit. For scientific or technical applications where precision is crucial, all significant digits are preserved in the calculation process.
Unit Selection Guide
• Kilograms (kg): Standard SI unit, used in scientific and international contexts
• Grams (g): For smaller weights in laboratory and cooking applications
• Milligrams (mg) & Micrograms (μg): For very small measurements in pharmaceutical and laboratory work
• Pounds (lb) & Ounces (oz): Common in US and UK for everyday measurements
• Stone (st): Traditional British unit for body weight
• US Tons: For very large weights in industrial applications
1. What is the difference between weight and mass?
Weight is the force of gravity acting on an object's mass. While mass remains constant regardless of location, weight can vary depending on gravitational field strength. However, for practical purposes on Earth, weight and mass units are often used interchangeably since gravity is relatively constant.
2. Why are there different weight units?
Different weight units evolved historically in various regions and for different purposes. The metric system (kg, g) was developed for scientific consistency, while imperial units (lb, oz) emerged from traditional usage. Today, both systems coexist, making conversion tools necessary for international communication and trade.
3. How accurate are the conversions?
The calculator uses precise conversion factors defined by international standards. For example, the kilogram-to-pound conversion uses the exact factor of 2.20462262185 pounds per kilogram. Results are displayed with six decimal places to ensure accuracy for both large and small measurements.
4. Which unit should I use for my measurements?
The choice of unit depends on your application. For scientific work, metric units (especially kg and g) are preferred. For everyday measurements in English-speaking countries, pounds and ounces are common. For very small quantities, mg or μg are appropriate, while tons are used for very large weights.
5. What is the scientific source for this calculator?
This calculator uses conversion factors established by the International Bureau of Weights and Measures (BIPM) and the National Institute of Standards and Technology (NIST). The kilogram is defined by the Planck constant, and all other weight units are derived from this definition. The conversion factors are based on exact relationships defined in the International System of Units (SI) and legal standards for non-SI units.