⚖️ Weight Converter

Enter a value and pick its unit — every other unit updates instantly below.

Value

Unit

The pound sets everything else

Since 1959 the pound has had an exact metric definition, and the ounce, stone and short ton are all defined from it. The converter works in kilograms:

1 lb      = 0.45359237 kg exactly
1 oz      = 28.349523125 g   = 1/16 lb
1 stone   = 6.35029318 kg    = 14 lb
1 US ton  = 907.18474 kg     = 2,000 lb   (short ton)
1 tonne   = 1,000 kg         = 2,204.62 lb

So 150 lb is 150 × 0.45359237 = 68.04 kg, and 1 kg is 2.204623 lb. Doubling kilograms and adding 10% gets you within half a pound, which is enough for a luggage scale.

Body weight in three systems

Kilograms	Pounds	Stone and pounds
50	110.23	7 st 12.2 lb
60	132.28	9 st 6.3 lb
70	154.32	11 st 0.3 lb
80	176.37	12 st 8.4 lb
90	198.42	14 st 2.4 lb
100	220.46	15 st 10.5 lb

Stones are read off the Stones row as a decimal, so 11.023 st means 11 stone and 0.023 × 14 = 0.3 lb. Britain and Ireland still use stones for people; nowhere else does.

The ounce here is the avoirdupois ounce of 28.3495 g, used for food and post. Precious metals are priced in troy ounces of 31.1035 g, about 10% heavier, so a one ounce gold coin weighs 31.1 g and not 28.3 g. Converting a gold price with this tool would undercount it.

Frequently asked questions

How many kg is 150 pounds?

68.04 kg. The factor is 0.45359237, so a rough version is to halve the pounds and take off 10%: half of 150 is 75, less 10% is 67.5, which is within a kilogram.

How many pounds are in a stone?

14 pounds, or 6.35 kg. So 11 stone is 154 lb and 69.85 kg, and a weight of 11 st 7 lb is 161 lb or 73.03 kg.

Is a US ton the same as a metric tonne?

No. A US short ton is 2,000 lb or 907.18 kg, a metric tonne is 1,000 kg or 2,204.62 lb, and the British long ton is 2,240 lb or 1,016.05 kg. This tool offers the short ton and the tonne.