Weight Converter

Convert weights between kilograms, pounds, ounces, grams, and specialized units including precious metals. Get instant, accurate results for all your weight conversion needs.

Weight Converter

Convert weights between metric, imperial, and specialized units including precious metals

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Click on any weight to convert it

Understanding Weight and Mass Measurements

Weight and mass are fundamental measurements in science, commerce, and daily life. While technically different (mass measures matter, weight measures gravitational force), the terms are often used interchangeably in everyday contexts. Understanding different weight units and their relationships is essential for accurate measurements across various applications.

Metric System

The metric system provides a decimal-based approach to weight measurement, making conversions straightforward and calculations simple. It's the global standard for science and most countries.

• Gram (g): Base unit for small weights
• Kilogram (kg): 1000 grams, SI base unit
• Metric ton (t): 1000 kilograms
Used globally in science and commerce

Imperial System

The imperial system uses traditional units that remain common in the United States and some other countries. These units have historical origins and specific relationships.

• Ounce (oz): 1/16 of a pound
• Pound (lb): 16 ounces, approximately 454g
• Stone (st): 14 pounds (British)
• Ton: 2000 pounds (US) or 2240 pounds (UK)

Precious Metals

Precious metals use specialized weight units that provide precision for valuable materials. These units are essential in jewelry, investment, and industrial applications.

• Carat (ct): 200 milligrams, for gemstones
• Troy ounce (oz t): 31.1g, for precious metals
• Pennyweight (dwt): 1/20 troy ounce
• Grain (gr): Smallest traditional unit

Scientific Applications

Scientific measurements require precise weight units for research, medicine, and manufacturing. Accuracy and consistency are critical for reproducible results.

• Laboratory measurements and chemical reactions
• Medical dosages and pharmaceutical preparations
• Quality control in manufacturing
• Research data standardization

Weight Conversion Guide

Mastering weight conversions requires understanding the mathematical relationships between different measurement systems. Here are the key conversion factors and methods for accurate weight calculations.

Common Conversions

Metric System:
1 kg = 1000 g
1 t = 1000 kg
1 mg = 0.001 g

Imperial System:
1 lb = 16 oz
1 st = 14 lb
1 ton (US) = 2000 lb

Cross-System Conversions

Metric to Imperial:
1 kg = 2.205 lb
1 g = 0.035 oz
1 t = 2204.6 lb

Imperial to Metric:
1 lb = 453.592 g
1 oz = 28.35 g
1 ton (US) = 907.2 kg

Precious Metal Conversions

Troy System:

• 1 troy oz = 31.1035 g
• 1 troy oz = 20 pennyweights
• 1 pennyweight = 1.555 g
• 1 grain = 64.8 mg

Gemstone Weights:

• 1 carat = 200 mg = 0.2 g
• 5 carats = 1 gram
• 1 carat = 4 grains
• Used for diamonds and gems

Practical Applications

Everyday Use

Weight conversions appear in many daily situations, from cooking and shopping to fitness and health monitoring.

• Cooking and recipe measurements
• Body weight tracking and fitness
• Package shipping calculations
• Shopping and price comparisons
• Luggage weight limits for travel

Professional Applications

Professional fields require precise weight measurements for quality control, safety, and regulatory compliance.

• Medical dosages and prescriptions
• Manufacturing quality control
• Precious metal trading and jewelry
• Chemical formulations
• Construction material calculations

Weight Conversion Examples

Everyday Examples

Body Weight:
70 kg person = 154.3 lbs
= 11 stones (British)

Cooking:
500g flour = 1.1 lbs
= 17.6 oz

Luggage:
23 kg limit = 50.7 lbs
Standard airline allowance

Precious Metal Examples

Gold Bar:
1 troy oz = 31.1 g
= 20 pennyweights

Diamond:
1 carat = 0.2 g
= 200 milligrams

Silver Coin:
1 oz silver = 28.35 g
≠ 1 troy oz (31.1 g)

Common Mistakes and Tips

Common Mistakes

×
Confusing troy and regular ounces: Troy ounces (31.1g) are heavier than regular ounces (28.35g)
×
Using wrong ton type: US tons (2000 lbs) vs UK tons (2240 lbs) vs metric tons (1000 kg)
×
Precision errors: Rounding too early in multi-step conversions

Best Practices

✓
Know your context: Verify which measurement system and units are expected
✓
Use appropriate precision: Match decimal places to your measurement accuracy
✓
Double-check critical conversions: Especially for medical, legal, or financial applications

Frequently Asked Questions

What's the difference between mass and weight?

Mass is the amount of matter in an object (measured in kg), while weight is the force gravity exerts on that mass (measured in Newtons). In everyday use, the terms are used interchangeably, and our converter handles both concepts.

Why are troy ounces different from regular ounces?

Troy ounces (31.1g) are about 10% heavier than avoirdupois ounces (28.35g). The troy system was developed for precious metals and remains the standard for gold, silver, and other valuable materials.

How accurate should weight conversions be?

Accuracy depends on your application. Cooking typically needs 1-5% accuracy, while scientific applications may require 0.1% or better. Medical dosages require extreme precision and should always be verified by professionals.

What's the best way to remember common conversions?

Key conversions to memorize: 1 kg ≈ 2.2 lbs, 1 oz ≈ 28g, 1 lb ≈ 454g. For precious metals: 1 troy oz ≈ 31g. These approximations work well for quick mental calculations.

Weight Converter