Mass & Weight Converter ⚖️
Free online mass and weight converter. Convert kg to lbs, pounds to kilograms, grams, ounces, tons and 18+ mass units instantly. Includes kg to pounds calculator with formulas.
📐 Conversion Formula
Common Mass & Weight Conversions
Quick Mass Conversions
kg to lbs
× 2.20462
1 kg = 2.205 lbs
lbs to kg
× 0.453592
1 lb = 0.454 kg
g to oz
÷ 28.35
100 g = 3.53 oz
kg to g
× 1,000
1 kg = 1,000 g
Converter Performance Metrics
How to Use Mass Converter
Step 1: Enter Mass Value
Type the mass or weight value you want to convert in the "From" field. The converter accepts any positive or negative number including decimals. For example, enter 50 for 50 kilograms or 150 for 150 pounds depending on your selected unit.
Step 2: Select Source Unit
Choose the unit of your input mass from the "From" dropdown. Options include kilograms, pounds, grams, ounces, stones, tons, tonnes, carats and 18+ other mass units. Select the unit that matches your measurement.
Step 3: Select Target Unit
Pick the unit you want to convert to from the "To" dropdown. The conversion happens automatically in real-time as you change units. The formula used for conversion is displayed below the converter for reference and verification.
Step 4: Use Results
View the converted result in the "To" field. Click Copy to copy the result to clipboard, Swap to reverse conversion direction, or Reset to start over. All calculations are instant and highly accurate for scientific and everyday use.
Understanding Mass & Weight Units
What is Mass vs Weight?
Mass is the amount of matter in an object, measured in kilograms (kg) or grams (g). Weight is the force exerted by gravity on that mass, measured in newtons (N). In everyday usage, mass and weight are used interchangeably. The SI base unit of mass is the kilogram, defined by the Planck constant since 2019.
Key Relationships: \( 1 \text{ kg} = 1,000 \text{ g} = 2.20462 \text{ lbs} \), \( 1 \text{ lb} = 0.453592 \text{ kg} = 16 \text{ oz} \), \( 1 \text{ tonne} = 1,000 \text{ kg} \), \( 1 \text{ ton (US)} = 2,000 \text{ lbs} \), \( 1 \text{ stone} = 14 \text{ lbs} = 6.35 \text{ kg} \). Weight formula: \( W = mg \) where \( m \) is mass and \( g \) is gravitational acceleration.
Common Mass Units Explained
Kilogram (kg): SI base unit of mass. One kg is mass of International Prototype Kilogram (now defined by Planck constant). Common for body weight, food, and general measurements. Most countries use kg as standard mass unit.
Pound (lb): Imperial/US customary unit. One pound equals 0.453592 kg. Used primarily in USA for body weight, food portions, and everyday measurements. Abbreviated as "lb" from Latin "libra" meaning balance or scales.
Stone: British imperial unit equal to 14 pounds or 6.35 kg. Used mainly in UK and Ireland for human body weight. Person might weigh "10 stone" (140 lbs or 63.5 kg). Less common in other English-speaking countries.
Common Use Cases
🏋️ Health & Fitness
Convert body weight between kg and lbs for fitness tracking, medical records, and nutrition planning. Understanding your weight in different units helps when using international fitness programs, comparing medical data, or traveling to countries using different measurement systems.
🍳 Cooking & Baking
Convert recipe ingredients between grams, ounces, and pounds. International recipes may use different units—American recipes use oz/lbs, European use g/kg. Accurate conversions ensure recipe success and consistent results across different measurement systems.
📦 Shipping & Logistics
Convert package weights for international shipping, freight calculations, and customs documentation. Carriers may use different units—UPS/FedEx in USA use lbs, international carriers use kg. Accurate weight conversions prevent shipping errors and additional costs.
💎 Jewelry & Precious Metals
Convert between carats, troy ounces, and grams for gemstones, gold, silver, and precious metals. Troy ounce (31.1g) differs from regular ounce (28.3g). Essential for jewelry appraisals, precious metal trading, and understanding international commodity prices.
🏗️ Construction & Engineering
Convert material weights between tonnes, tons, and pounds for construction projects, structural calculations, and load specifications. Tonne (metric ton = 1,000 kg) differs from US ton (2,000 lbs) and UK ton (2,240 lbs). Critical for safe design and material ordering.
🎓 Education & Science
Students and researchers convert mass units for chemistry experiments, physics problems, and laboratory work. Understanding unit conversions fundamental to scientific literacy. Essential for homework, lab reports, and comparing experimental data across different publications and standards.
