Stone, Kilograms & Pounds Converter (UK)

14 stone is exactly 196 pounds (1 stone = 14 lb by definition). It's also 88.9 kg. The stone is a specifically British unit — most other English-speaking countries use only pounds for body weight. So 14 stone is sometimes a confusing figure to quote to American friends or fitness apps that don't recognise stones.

70 kg is 11 stone 0 lb, or 154.3 lb total. The maths: 70 kg × 2.2046 = 154.3 lb. Divide by 14 to get stones: 154.3 ÷ 14 = 11.02, so 11 whole stones with 0.3 lb remainder (rounded to 0 lb in the composite format). 70 kg is also a useful reference because it's roughly the middle of the NHS healthy-weight range for an average-height adult.

80 kg is 12 stone 8 lb, or 176.4 lb total, or 12.6 stones in decimal form. UK adults often describe their weight as "12 and a half stone" — that's exactly 12 st 7 lb, or 79.4 kg, so 80 kg is very slightly heavier than that. For NHS BMI calculations they'll use 80 kg with your height in metres; for casual conversation, 12 st 8 lb is the form most British adults still recognise.

100 kg is 15 stone 10 lb, or 220.5 lb total. In decimal form, 100 kg is 15.75 stones. This is a useful weight to remember as a rough threshold — 100 kg often triggers the upper end of standard medical equipment weight ratings (gym machines, hospital beds, stretchers) and the upper bracket for many airline checked-baggage limits when combined with bag weight.

Multiply kilograms by 0.157473 to get stones (decimal). For the UK "X st Y lb" composite format: convert kg to pounds first by multiplying by 2.2046, then divide pounds by 14 — the whole number is stones, the remainder × 14 gives pounds. Worked example: 75 kg × 2.2046 = 165.35 lb. 165.35 ÷ 14 = 11 stones with 11.35 lb remainder, so 75 kg = 11 st 11 lb. The converter does this automatically.

Multiply pounds by 0.453592 to get kilograms. So 150 lb is 68.04 kg, 180 lb is 81.65 kg, 200 lb is 90.72 kg. The conversion is exact because 1 pound is defined as exactly 0.45359237 kg. For quick mental maths, divide pounds by 2.2. UK fitness apps and gym equipment often default to kg; American apps and US-import equipment often use lb.

UK hospitals weigh newborns in grams (e.g. "3,400 grams"); parents typically convert to the old pounds-and-ounces format. 1 kg = 2.2046 lb, then multiply the decimal by 16 for ounces. So 3,400 g = 3.4 kg = 7.495 lb = 7 lb 8 oz (rounded). A typical UK newborn weighs 2.5–4.5 kg (5 lb 8 oz to 9 lb 15 oz). The baby weight converter above handles this directly.

The NHS uses BMI (Body Mass Index): healthy is 18.5–24.9 for adults of European descent, with lower thresholds for South Asian, Chinese and Black African/Caribbean adults (NICE NG7 sets healthy upper limit at 23). To find your healthy weight range: multiply 18.5 and 24.9 by your height in metres squared. For someone 1.75 m tall, that's 56.6 kg to 76.3 kg, or 8 st 13 lb to 12 st 0 lb. Use our BMI calculator for your specific figure.

Mostly cultural inertia. Stones were the legal trading unit in the UK for body weight until decimalisation in 1971, and they survived in conversational use even as medicine and science went metric. The number "feels" more manageable than the same weight in pounds (13 stone vs 182 lb) and more relatable than kilograms for people who grew up with stones. Almost nowhere else uses stones — Ireland abandoned them earlier, the US never adopted them. UK retailers selling clothing and luggage to international markets default to kg.