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⚖️ Weight Converter

Convert between kilograms, pounds, grams, ounces, and tonnes instantly.

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Weight Unit Conversion — When You Need It and Why

This converter handles conversions between kilograms (kg), pounds (lb), grams (g), ounces (oz), and metric tonnes (t). These five units cover the full range of weight measurement from a few grams up to thousands of kilograms. All conversions are anchored to the kilogram as the SI base unit of mass, with exact defined relationships: 1 lb = 0.45359237 kg (exact), 1 oz = 28.3495 g, and 1 metric tonne = 1,000 kg.

Body weight is the most personal use case. In and most of the world, body weight is measured in kilograms. In the UK, stone and pounds are still commonly used in personal contexts (though stone is not available in this converter — 1 stone = 14 pounds = 6.35 kg). In the US, pounds are standard. If you follow a US fitness programme or use American health apps, converting your weight between kg and lbs is a routine need.

Cooking and food: recipes using imperial measurements call for ounces and pounds. A recipe requiring 16 oz of flour is 453 g. Knowing that 1 oz ≈ 28 g lets you quickly estimate conversions without a calculator. Nutritional information on imported products is sometimes listed per serving in ounces, while labels use grams — converting accurately matters when tracking macros or comparing products.

Freight and shipping: courier and freight services charge by weight. If a shipping rate calculator quotes a price per kilogram and your shipment is measured in pounds (common with US-origin goods), you need to convert. 10 lbs = 4.54 kg. Volumetric weight (a formula based on dimensions rather than actual weight) is separate from actual weight and is used when a package is large but light — but actual weight conversion is always the starting point.

For dedicated KG-to-LBS conversion with a comprehensive reference table, see the KG to LBS Converter on CalForge.

How to Convert Between Weight Units

Weight conversion uses fixed ratios between units. Key conversions: 1 kilogram = 2.20462 pounds = 35.274 ounces. 1 pound = 0.453592 kg = 16 ounces. 1 stone (UK) = 14 pounds = 6.35 kg. 1 metric tonne = 1,000 kg = 2,204.6 pounds.

Weight conversions are needed in fitness, cooking, shipping, medical records, scientific work, and international commerce. Using the wrong unit in a medical or engineering context can cause serious errors — always confirm which system is expected before recording or transmitting weight data.

Frequently Asked Questions

How many kg is 1 stone? +
1 stone = 14 pounds = 6.35029 kilograms. This unit is primarily used in the UK and Ireland for body weight. To convert stones and pounds to kg: multiply stones by 6.35, then add pounds × 0.453. Example: 11 stone 4 pounds = (11×6.35) + (4×0.453) = 69.85 + 1.81 = 71.66 kg.
How do I convert ounces to grams? +
Multiply ounces by 28.3495. Example: 8 oz = 8 × 28.35 = 226.8g. Common cooking conversions: 1 oz = 28g; 4 oz = 113g; 8 oz = 227g; 16 oz (1 lb) = 454g.
Why does the UK use both metric and imperial weight units? +
The UK officially adopted metric in the 1960s-70s but retained imperial units in everyday contexts: body weight in stones/pounds, food market sales in pounds/ounces (informally), and some construction contexts. The coexistence of both systems is a practical legacy of incomplete metrication.