Convert Weight Units

Weight Converter

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Weight Conversion Chart

Quick reference for the most common weight and mass unit relationships.

Metric (SI) Mass Units

1 tonne (t)=1,000 kg
1 kg=1,000 g
1 g=1,000 mg
1 g=0.001 kg

Imperial / US Customary

1 stone (st)=14 pounds
1 pound (lb)=16 ounces
1 short ton=2,000 lb
1 long ton=2,240 lb

Cross-System (Exact Factors)

1 lb=0.45359237 kgexact
1 oz=28.349523125 gexact
1 st=6.35029318 kgexact
1 short ton=907.18474 kgexact
1 long ton=1,016.0469088 kgexact

These cross-system factors are exact by definition, established by the International Yard and Pound Agreement (1959). 1 pound is defined as exactly 0.45359237 kilograms.

Weight Units by Use Case

Body Weight

Track body weight with the units your region uses. The US reports in pounds (lb), the UK uses stones and pounds (st + lb), and most other countries use kilograms (kg). Medical records worldwide increasingly use kg. 1 kg = 2.205 lb = 0.157 st.

Cooking & Baking

Recipe measurements vary by country. US recipes use ounces (oz) and pounds, while European and Asian recipes use grams (g) and kilograms. Precision matters in baking — a kitchen scale in grams gives the most consistent results. 1 oz ≈ 28.35 g (exact: 28.349523125 g).

Shipping & Logistics

Airlines and couriers use kilograms internationally (checked bag: 23 kg) and pounds in the US (50 lb). Freight uses metric tons (1,000 kg) or short tons (2,000 lb) in the US. 1 metric ton = 2,204.6 lb.

Science & Medicine

Scientific work uses the SI system: kilograms for mass, grams for smaller quantities, and milligrams for medication dosages. Drug doses are often calculated per kg of body weight. 1 kg = 1,000 g = 1,000,000 mg.

In everyday language, "weight" and "mass" are used interchangeably. Technically, the kilogram and pound measure mass. Weight is a force that depends on gravity. For conversions on Earth's surface, the distinction does not affect the result.

Frequently Asked Questions

What weight converters are available?

CoolConversion offers over 20 free weight converters covering all common pairs (kg to lbs, lbs to kg, stones to kg, and more), plus compound converters like Kg to Stones & Pounds and a Universal Weight Converter supporting 100+ units.

How do I convert kg to stones and pounds?

Use our Kg to Stones and Pounds converter. Simply enter the kg value, and it instantly shows the result in stones and pounds (UK weight system). For example, 75 kg = 11 stones 11 pounds.

What is the difference between metric and imperial weight systems?

The metric system uses kilograms and grams, while the imperial system (US/UK) uses pounds, ounces, and stones. 1 kg = 2.20462 pounds. The UK also uses stones (1 stone = 14 pounds = 6.35029 kg).

Can I convert between any weight units?

Yes, our Universal Weight Converter supports 100+ weight and mass units including metric (kg, g, mg, tonnes), imperial (lbs, oz, stones), US customary, and specialized units for various applications.

Conversion Charts & Tables

Printable charts and reference tables for common weight conversions:

Specialized Converters

Compound-unit converters with multi-unit outputs for body weight tracking, cooking, and shipping.

Compound Weight Converters

  • Kg to Stones and Pounds

    Converts kilograms to stones AND remaining pounds (e.g., 75 kg = 11 st 11 lbs). Essential for UK body weight.

  • Kg to Lbs and Oz

    Converts kilograms to pounds AND remaining ounces (e.g., 3.5 kg = 7 lbs 11 oz). Ideal for cooking and baby weight.

  • Stones and Pounds to Kg

    Input stones plus pounds, get kilograms (e.g., 11 st 7 lbs = 72.57 kg).

  • Pounds and Ounces to Kg

    Input lbs plus oz, get kilograms (e.g., 12 lbs 14 oz = 5.84 kg).

  • Pounds to Stones and Lbs

    Convert total pounds to stones + remaining pounds (e.g., 150 lbs = 10 st 10 lbs).

Conversion factors verified against NIST (National Institute of Standards and Technology), BIPM (International Bureau of Weights and Measures) 1 lb = 0.45359237 kg by international agreement (1959). Last reviewed: March 2026
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.