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Weight Converter | Online Gram/Kilogram/Pound/Ounce Unit Conversion Tool

Instantly convert weights between metric, imperial, precious metal, and pharmaceutical units. Supports high-precision conversion from nanograms to tons with professional-grade accuracy.

What is a Weight Converter?

Weight units are standards for measuring the mass of objects. Different unit systems are suitable for different applications: the metric system is based on grams and widely used in scientific research and international trade; the imperial system is based on pounds and used in English-speaking countries; precious metal units are used for jewelry and precious metal trading; pharmaceutical units are used for precise medical compounding.

Weight Unit Systems

Metric System

International System of Units (SI), based on grams

Base Unit: Gram (g)

Common Units: Milligrams, grams, kilograms, tonnes

Imperial System

Traditional Anglo-American units, based on pounds

Base Unit: Pound (lb)

Common Units: Ounces, pounds, stones, tons

Precious Metal Units

Specialized units for precious metal trading

Base Unit: Troy Ounce (oz t)

Common Units: Troy ounces, troy pounds, carats

Pharmaceutical Units

Precision units for medical compounding

Base Unit: Grain (gr)

Common Units: Grains, scruples, drachms

Key Features

Support 40+ weight unit conversions
High-precision calculation engine
Smart unit recommendations
Visual weight comparisons
Batch processing support
Professional application modes
Conversion history tracking
Real-time conversion preview

Weight Unit Converter

Convert between metric, imperial, precious metal, and pharmaceutical units

Adjust decimal places

6

Weight Scale Visualization

Explore weight ranges from microscopic to macroscopic

Microscopic Weight

Atomic and molecular world

Microscopic Scale: Atomic and molecular world
1 ng
10⁻⁹ g
1 μg
10⁻⁶ g
1 mg
10⁻³ g
1 g
10⁰ g
1 kg
10³ g
1 t
10⁶ g
1-1000 ng
Atomic Scale
• Virus particle (~100 ng)
• DNA fragment (~1 ng)
• Protein molecule (~10 ng)
Click to convert quickly
1-1000 μg
Cellular Scale
• Bacteria (~1 μg)
• Human cell (~10 μg)
• Pollen grain (~100 μg)
Click to convert quickly
1-1000 mg
Small Objects
• Mosquito (~2 mg)
• Pill (~500 mg)
• Paper clip (~1000 mg)
Click to convert quickly
Microscopic World
The microscopic scale uses logarithmic representation to show the tiny world from subatomic particles to cellular structures, revealing the basic building blocks of matter.

Conversion Examples

Click any example for quick conversion

1 kilogram =
1000 g • 2.20 lb • 35.27 oz • 1000000 mg
Click to convert 1 kilogram
1 pound =
16 oz • 453.6 g • 0.454 kg • 7000 gr
Click to convert 1 pound
1 troy ounce =
31.1 g • 1.097 oz • 20 dwt • 155.5 ct
Click to convert 1 troy ounce

Common Use Cases

Scientific Research

Chemical experiments, physical measurements, biological samples with nanogram to kilogram precision. Our high-precision calculations ensure experimental data accuracy, supporting scientific notation for extremely small or large values.

  • • Protein molecular weight determination
  • • Chemical reagent precise preparation
  • • Biological sample mass analysis

Industrial Manufacturing

Material ratios, product specifications, quality control with batch processing support. Batch conversion functionality can handle large amounts of production line data, improving work efficiency.

  • • Raw material ratio calculations
  • • Product quality testing
  • • Production cost accounting

International Trade

Cargo weight calculations, shipping costs, customs documentation with metric-imperial conversion. Ensures accuracy of weight data in international trade, avoiding economic losses due to unit errors.

  • • Cargo weight declaration
  • • Shipping cost calculation
  • • Customs document completion

Pharmaceutical

Drug dosage calculations, prescription compounding, clinical research with pharmaceutical units. Pharmaceutical units like grain and scruple require extremely high precision to ensure medication safety.

  • • Drug dosage conversion
  • • Prescription unit conversion
  • • Clinical trial data

Jewelry & Precious Metals

Gold, silver, gemstone trading with troy ounce, carat, and pennyweight conversions. Precious metal trading requires precise weight calculations, we provide international standard conversion factors.

  • • Gold weight calculation
  • • Gemstone carat conversion
  • • Precious metal trading

Cooking & Baking

Recipe conversions between ounces, grams, pounds for international cooking. Helps chefs and bakers accurately convert weight units in recipes from different countries, ensuring cooking results.

  • • Recipe unit conversion
  • • Baking ingredient calculation
  • • International recipe adaptation

Frequently Asked Questions

What weight units are supported?

Our tool supports metric (mg, g, kg, tonnes), imperial (oz, lb, stones), and specialized units (carats, grains) with high precision.

What's the difference between mass and weight?

Mass is the amount of matter (constant), weight is the force of gravity on that mass (varies by location). Our tool converts mass units.

When should I use stones as a unit?

Stones are primarily used in the UK and Ireland for measuring body weight (1 stone = 14 pounds = 6.35 kg).

What are carats used for?

Carats measure gemstone weight (1 carat = 200 mg). Not to be confused with karat, which measures gold purity.

How precise are the conversions?

Our conversions use exact mathematical relationships and display results with appropriate precision for each unit type.