Weight Converter (kg / stone / pounds)

The UK uses a mix of metric and imperial weight measurements. Metric, meaning kilograms and grams, is standard in shops and on packaging by law, but many people still think in stones and pounds for body weight. This converter handles kilograms, pounds, stones and ounces, and shows results in the format most commonly used in UK daily life, so body weight comes back in stones and pounds while food appears in kilograms or grams.

One stone equals 14 pounds, and one pound equals 0.4536 kilograms. Following the chain through, a stone is 6.350 kg, a pound is 16 ounces or 453.6 g, and a kilogram is 2.205 lb or 0.1575 st. That puts 70 kg at 11st 0.4lb, while 75 kg works out at 165.35 lb, which is 11 stone 11.35 lb or 2,645.55 oz. Where each unit is used says something about British habits, since supermarkets price produce in kilograms, gyms label plates in kilograms, NHS records are kept in kilograms only and driving licences have used kilograms for vehicle weights since 2014, yet people still describe themselves as 12st 5lb.

For quick sums in your head, multiply kilograms by 2.2 to reach pounds and divide pounds by 2.2 to come back, with 2.205 the precise figure. Stones convert to kilograms by multiplying by 6.35. Those shortcuts give 80 kg as roughly 176 lb or 12st 8lb, 12 stone as 76.2 kg and 100 lb as 45.4 kg. Babies in Britain are weighed in pounds and ounces, with 7lb 5oz a typical birth weight, and medical records switch to kilograms by the age of 1. Weight training keeps to kilograms, where a 100kg bench press is 220lb and a standard barbell of 20kg weighs 44lb, and aviation cargo is kilograms only.

Healthy weight ranges come from BMI, which divides weight in kilograms by height in metres squared. Someone 1.75m tall, or 5'9", counts as underweight below 56.7kg (8st 13lb), healthy between 56.7kg and 76.6kg (8st 13lb to 12st 0lb), overweight from 76.6kg to 91.9kg, and obese at 91.9kg or above, which is 14st 6lb. The healthy band shifts with height, running 47-64kg at 1.60m, 53-72kg at 1.70m and 60-81kg at 1.80m. Asian populations use lower thresholds, with overweight starting at a BMI of 23. BMI cannot tell muscle from fat, so it is worth reading alongside waist circumference, where under 94cm for men and under 80cm for women is the usual marker.

Cooking is where the two systems collide most often. American recipes measure by volume in cups while British ones measure by weight in grams, and the two are not interchangeable across ingredients. A US cup of flour is 125g, of sugar 200g, of butter 227g, of rice 200g and of milk 240g. The cups themselves differ too, since a UK Imperial cup holds 284ml against 237ml for the US version, so it pays to check where a recipe came from. Spoons are safer ground, with a tablespoon at 15ml in both countries and a teaspoon at 5ml everywhere. For baking in Britain, weighing in grams remains the accurate route.

Weight also decides what you may drive and what you can post. A standard category B licence covers vehicles up to 3,500kg maximum authorised mass, C1 takes you from 3,500kg to 7,500kg, and category C covers HGVs above 7,500kg. Bridge limits are signed in tonnes, where one tonne is 1,000kg, equal to 0.984 long tons in the old UK measure or 1.102 US tons. Royal Mail treats anything up to 2kg as a small parcel and up to 20kg as medium, while over 30kg needs a pallet courier. Airline hand luggage usually tops out somewhere between 7kg and 10kg.