Convert kilograms, pounds, ounces, stone, US and UK tons, troy ounces, carats and more — then go further with dedicated body-weight, cooking, and gym converters, full reference tables, and worked examples.
15units
4converter modes
16FAQs answered
01Universal converter
Enter any weight, pick any two of the 15 units. Every factor is the exact published definition — the pound is 453.59237 g by the 1959 international agreement — so results match reference tables to full precision.
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02Converters by context
The same exact factors, shaped for the three places weight conversions actually happen: the bathroom scale, the kitchen, and the gym.
Body-weight converter
See your weight in kilograms, pounds, and UK stone + pounds — the format bathroom scales and doctors' offices in Britain actually use.
Cooking converter
Recipe in ounces but your scale reads grams? Convert instantly, then check the ingredient table for cup weights.
Ingredient weights — grams per US cup
Gym plate converter
Traveling, or following a program written in the other system? Every standard plate and Olympic bar, both ways.
Standard equivalents: 20 kg = 44.09 lb · 25 kg = 55.12 lb · 45 lb = 20.41 kg. Fractional plates (1.25 kg / 2.5 lb) included in the universal converter above.
Reference tables
One kilogram and one pound, expressed in all 15 units — handy when a manual only gives one system.
1 kilogram =
1 pound =
03Worked examples
Every result below was computed by the engine on this page — change the inputs above and re-run them yourself.
Example 1 — Pounds to kilograms (body weight)
150 lb × 0.45359237 kg/lb
= 68.0388555 kg
Answer: 150 lb = 68.0389 kg (10 st 10 lb)
Example 2 — Kilograms to pounds
1 kg ÷ 0.45359237 kg/lb
= 2.20462262 lb
Answer: 1 kg = 2.20462 lb
Example 3 — Ounces to grams (baking)
8 oz × 28.349523125 g/oz
= 226.796185 g
Answer: 8 oz flour = 226.796 g (≈ 227 g)
04Methodology & sources
All conversions go through grams: result = value × (grams per from-unit) ÷ (grams per to-unit). The factors are exact published definitions, not approximations:
Pound: exactly 453.59237 g (1959 international yard and pound agreement).
Ounce: exactly 28.349523125 g = 1/16 lb. Stone: exactly 14 lb = 6,350.29318 g.
US short ton: 2,000 lb = 907,184.74 g. UK long ton: 2,240 lb = 1,016,046.9088 g. Metric tonne: 1,000,000 g.
Grain: 1/7,000 lb = 0.06479891 g. Dram: 1/256 lb = 1.7718451953125 g.
Troy ounce: 31.1034768 g (480 grains) — precious metals. Carat: 0.2 g — gemstones.
⚖️ Scope boundary: this hub vs the legacy weight-to-mass-converter
The legacy weight-to-mass-converter is a one-dimensional converter — enter a number, pick two units, done. This page (#299) is a full weight workspace: 15 units across metric, avoirdupois, US and UK customary, troy and gemstone systems, plus body-weight (stone/lb breakdown), cooking, and gym context converters, full reference tables, and worked examples. Use the legacy tool for a quick two-unit conversion; use this hub when you need context.
Ingredient cup weights are standard US reference values (e.g. all-purpose flour 120 g/cup, granulated sugar 200 g/cup, butter 227 g/cup) — actual weights vary by brand and packing, so treat them as kitchen-accurate, not laboratory-accurate. Gym plate values are nominal manufacturer ratings. Everything on this page computes locally in your browser; no data is sent anywhere.
05Frequently asked questions
The exact questions people ask about weight conversion, answered with the engine's own numbers.
How many pounds are in a kilogram?
One kilogram equals exactly 2.20462262 pounds, usually rounded to 2.20462 lb. The pound is defined as exactly 0.45359237 kg by the 1959 international agreement, so 1 kg = 1 ÷ 0.45359237 = 2.20462262 lb. To convert kilograms to pounds, multiply by 2.20462.
How many kilograms are in a pound?
One pound equals exactly 0.45359237 kilograms. To convert pounds to kilograms, multiply by 0.45359237. Worked example: 150 lb × 0.45359237 = 68.0388555 kg, about 68.04 kg.
How many ounces are in a pound?
There are exactly 16 ounces in one avoirdupois pound. This is exact by definition: the international ounce is 1/16 of the international pound, or 28.349523125 grams. So 1 lb = 16 oz, and conversely 1 oz = 0.0625 lb.
How many grams are in an ounce?
One avoirdupois ounce equals exactly 28.349523125 grams. For everyday cooking, 28.35 g is plenty accurate. Do not confuse this with the troy ounce (31.1034768 g) used for precious metals — a kitchen "ounce" is always the avoirdupois ounce.
How many pounds are in a stone?
One stone equals exactly 14 pounds (about 6.35029 kg). The stone is still the standard body-weight unit in the UK and Ireland: someone who weighs 150 lb is 10 stone 10 lb. To convert stones to pounds, multiply by 14; to convert stones to kilograms, multiply by 6.35029318.
How do I convert stone to kilograms?
Multiply stones by 6.35029318. Worked example: 10 stone × 6.35029318 = 63.5029318 kg, about 63.5 kg. The reverse: kilograms to stones, divide by 6.35029318 — for example 70 kg ÷ 6.35029318 = 11.0231 stone, i.e. 11 st 0.3 lb.
What is the difference between a US ton, a UK ton, and a metric tonne?
Three different units share the name "ton": the US short ton is 2,000 lb = 907.18474 kg; the UK long ton is 2,240 lb = 1,016.0469088 kg; the metric tonne is 1,000 kg = 2,204.62 lb. So 1 metric tonne = 1.10231 US tons, and 1 UK ton = 1.01605 metric tonnes. Always check which ton a document means — freight, vehicle ratings, and fuel figures differ by country.
How many grams are in a troy ounce?
One troy ounce equals exactly 31.1034768 grams (480 grains). The troy ounce is used for gold, silver, and gemstones — never for groceries. Worked example: 100 g of gold ÷ 31.1034768 = 3.21507 troy ounces. A kitchen ounce (28.349523125 g) is about 9% lighter, so using the wrong ounce misprices metal.
How do I convert grams to ounces for cooking?
Divide grams by 28.349523125. Worked example: 8 oz of flour = 8 × 28.349523125 = 226.796 g, about 227 g. Quick kitchen anchors: 1 tablespoon of butter ≈ 14.2 g, one US stick of butter (4 oz) = 113.4 g, and 1 cup of all-purpose flour ≈ 120 g.
How many milligrams are in a gram?
Exactly 1,000 milligrams in one gram — the "milli-" prefix always means one-thousandth. Worked example: 250 mg = 0.25 g. Milligrams matter for supplements and medication: always double-check whether a label says mg or g, because a factor-1,000 mistake is dangerous.
What is a hundredweight (cwt)?
A hundredweight is a traditional bulk-trade unit with two definitions: the US hundredweight is exactly 100 lb (45.359237 kg) and the UK hundredweight is exactly 112 lb (50.80234544 kg), which is also 8 stone. The UK hundredweight survives in agricultural markets; the US hundredweight is still quoted in American commodity prices.
How do I convert my body weight from kg to stone and pounds?
Divide kilograms by 6.35029318 to get stones, then convert the decimal remainder to pounds (multiply by 14). Worked example: 70 kg ÷ 6.35029318 = 11.0231 stone → 11 whole stone, and 0.0231 × 14 = 0.32 lb, so 70 kg = 11 st 0.3 lb. The converter's body-weight tab does this automatically.
How many carats are in a gram?
Five carats make one gram, because the metric carat is defined as exactly 0.2 g. Carats measure gemstone weight, not gold purity — gold purity uses karat with a K (24K = pure gold). Worked example: a 2-carat diamond weighs 0.4 g.
How do I convert gym weights between kg and lb?
Multiply kilograms by 2.20462 for pounds, or pounds by 0.45359237 for kilograms. Standard plate equivalents: a 20 kg plate = 44.09 lb, a 25 kg plate = 55.12 lb, a 45 lb plate = 20.41 kg, a 35 lb plate = 15.88 kg. An Olympic barbell is 20 kg (44.09 lb) in most of the world and 45 lb (20.41 kg) in the US.
How is this different from the weight-to-mass-converter tool?
The legacy weight-to-mass-converter is a one-dimensional converter: enter a number, pick two units, done. This hub is a complete weight workspace: 15 units (metric, avoirdupois, US and UK customary, troy, carat, grain, dram), dedicated body-weight (stone/lb breakdown), cooking, and gym contexts, full reference tables, and worked examples with the exact published factors. If you only need a quick two-unit conversion, the legacy tool is fine — use the cross-link below.
Is this converter accurate, and is my data private?
Yes to both. Every factor is the exact published definition — the pound is 453.59237 g by the 1959 international agreement, the troy ounce is 31.1034768 g, the carat is 0.2 g — not a rounded approximation, so results match reference tables to full precision. And all calculations run 100% in your browser: no data ever leaves your device, nothing is uploaded or tracked.
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