Weight Converter

One scale reads kilograms, the recipe reads ounces, the gym plates are stamped in pounds and the British bathroom scale reports stones. A general weight converter saves you from chaining three separate calculations: enter a weight in whatever unit you have, and read it in the unit you actually need — kilograms, pounds, ounces, grams or stones.

Quick Answer

All weight conversions run through one anchor: 1 kilogram = 2.20462 pounds = 35.274 ounces = 1,000 grams, and 1 stone = 6.35029 kilograms (14 pounds). Convert your starting unit into kilograms first, then out into any other unit, and the factors agree in both directions.

The Main Units and How They Connect

The metric units are the simple part: grams and kilograms differ only by a factor of 1,000, and the tonne adds another 1,000 on top of the kilogram. The imperial and US customary units interlock differently. The avoirdupois pound is defined as exactly 0.45359237 kilograms and divides into 16 ounces, each of 28.349523125 grams. The stone, still the everyday body-weight unit in the UK and Ireland, is simply 14 pounds grouped together — a survival from older British practice that confuses everyone else on first meeting.

Because the pound is defined in terms of the kilogram, every conversion between the systems is exact: there is no measurement uncertainty in the factors themselves, only rounding in how many decimal places you choose to keep. That is worth remembering when two websites appear to disagree by a gram or two — they have rounded at different stages, and converting via kilograms in one pass, as this tool does, keeps the drift to a minimum.

Smaller and Older Weight Units You May Still Meet

A few specialised units survive in niches where this converter's list proves too short, and recognising them prevents expensive confusion. The grain — historically a single grain of wheat — is exactly 64.79891 milligrams and, remarkably, still measures bullets, arrowheads and some pharmaceutical doses today; there are exactly 7,000 grains in one pound. The carat used for gemstones is exactly 200 milligrams, so a one-carat diamond weighs 0.2 g — not to be confused with the karat that measures gold purity, a completely different scale wearing a nearly identical name.

British trade once ran on the hundredweight, which itself splits two ways: the imperial (long) hundredweight is 112 pounds, the American (short) one 100 pounds, and old invoices rarely say which they meant. Apothecaries' and troy units linger in antique recipes and precious-metal contexts, with their own ounces that do not match the everyday one. The general lesson the converter embodies still holds: before converting any historical or specialist figure, pin down which system the number was written in — the factor table above only governs the five everyday units it lists.

How to Use This Weight Converter

1. Enter the weight you have, as a number.
2. Select the unit that number is expressed in — grams, kilograms, ounces, pounds or stones.
3. Select the unit you want the answer in.
4. Read the converted value.
5. For body weight in stones and pounds, take the whole stones from the result and multiply the leftover fraction by 14 to get the remaining pounds.
6. Round sensibly for the context: grams for parcels and recipes, whole pounds for luggage, one decimal for body weight.

Worked Example: 85 Kilograms in Every Direction

A traveller weighs 85 kg and needs the figure for an American form, a British relative and a parcel scale. Into pounds: 85 ÷ 0.45359237 = 187.39 lb. Into ounces: 187.39 × 16 = 2,998 oz (or, directly, 85 × 35.274). Into stones: 187.39 ÷ 14 = 13.39 stone, which is spoken as 13 stone 5.4 lb — thirteen whole stones account for 182 lb, and the remaining 0.39 of a stone is 5.4 lb. One weight, three correct statements of it.

Kilogram-to-pound landmarks worth memorising:

• 1 kg = 2.20 lb
• 5 kg = 11.02 lb
• 10 kg = 22.05 lb
• 20 kg = 44.09 lb
• 50 kg = 110.23 lb
• 100 kg = 220.46 lb

Weights in Transport: Limits Written in Two Languages

Travel and freight constantly force conversions at the worst possible moment. The standard international checked-baggage allowance of 23 kg is 50.7 lb — which is why American carriers describe the same bag as a "50-pound limit" and occasionally argue about the missing 0.7 lb at the counter. Vehicle plates tell a similar story: a trailer or truck rated in kilograms for the European market carries a pounds figure in its American documentation, and towing safely means converting the gross vehicle weight rating, the trailer weight and the load into one consistent unit set before comparing them. Palletised freight is weighed in kilograms by most of the world's carriers regardless of where it started. In every case the safe routine is the one this tool follows: convert everything into a single unit first, compare like with like, and only then make the decision the weight was needed for.

Confusions This Converter Cannot Fix For You

It cannot know which "ton" you mean. A US (short) ton is 2,000 lb, a British (long) ton is 2,240 lb, and a metric tonne is 1,000 kg — about 2,204.6 lb. Shipping and industry documents specify which one; guessing wrong is a 10% error. It also cannot rescue a fluid-ounce reading: volume ounces of milk or oil must be turned into weight through the ingredient's density before any weight conversion applies.

For body weight specifically, expect the same person to "change" by a kilogram or more across a day with food, drink and clothing — conversion precision beyond one decimal place is meaningless on a bathroom scale. And when a result will be printed, shipped or prescribed, state the unit next to the number every time; more real-world harm has come from a correct number read in the wrong unit than from any rounding error.

Narrower Tools for Single Conversions

If you always make the same one conversion, a dedicated page is quicker: the lbs to kg converter and the kg to lbs converter each handle a single direction with nothing to configure. The complete set of unit pairs is collected under converters.