Weight and mass converter
Convert kg to lbs, grams to ounces, stone to kilos and tonnes to tons with exact factors, a two-way field and a full reference table.
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1 kg = 2.20462262185 lb
Automatic formatting keeps up to 12 significant digits and switches to scientific notation only for numbers past 10¹⁸ or below 10⁻⁹. You can paste values with thousands separators, and fractions such as 3/4 or 1 1/2 are understood too.
lb = kg × 2.20462262185
Your value: 1 × 2.20462262185 = 2.20462262185 lb
Kilogram: SI base unit of mass.
Pound: Exactly 0.45359237 kg since 1959.
| kg | lb |
|---|---|
| 1 | 2.20462262185 |
| 2 | 4.4092452437 |
| 3 | 6.61386786555 |
| 5 | 11.0231131092 |
| 10 | 22.0462262185 |
| 15 | 33.0693393277 |
| 20 | 44.092452437 |
| 25 | 55.1155655462 |
| 50 | 110.231131092 |
| 75 | 165.346696639 |
| 100 | 220.462262185 |
| 200 | 440.92452437 |
| lb | kg |
|---|---|
| 1 | 0.45359237 |
| 2 | 0.90718474 |
| 3 | 1.36077711 |
| 5 | 2.26796185 |
| 10 | 4.5359237 |
| 15 | 6.80388555 |
| 20 | 9.0718474 |
| 25 | 11.33980925 |
| 50 | 22.6796185 |
| 75 | 34.01942775 |
| 100 | 45.359237 |
| 200 | 90.718474 |
| Unit | Symbol | Value in kg | Notes |
|---|---|---|---|
| KilogramMetric | kg | 1 kg = 1 kg | SI base unit of mass. |
| GramMetric | g | 1 g = 0.001 kg | — |
| MilligramMetric | mg | 1 mg = 0.000001 kg | — |
| MicrogramMetric | µg | 1 µg = 0.000000001 kg | — |
| Tonne (metric ton)Metric | t | 1 t = 1,000 kg | Exactly 1,000 kg. |
| PoundImperial / US | lb | 1 lb = 0.45359237 kg | Exactly 0.45359237 kg since 1959. |
| OunceImperial / US | oz | 1 oz = 0.028349523125 kg | One sixteenth of a pound. |
| StoneImperial / US | st | 1 st = 6.35029318 kg | Exactly 14 pounds — UK body weight. |
| Short ton (US)Imperial / US | ton (US) | 1 ton (US) = 907.18474 kg | 2,000 pounds. |
| Long ton (UK)Imperial / US | ton (UK) | 1 ton (UK) = 1,016.0469088 kg | 2,240 pounds. |
| Troy ouncePrecious metal | oz t | 1 oz t = 0.0311034768 kg | Used for gold and silver. |
| CaratPrecious metal | ct | 1 ct = 0.0002 kg | Exactly 200 mg — gemstones. |
How to convert a weight
- Enter your figure in either box. Both fields are live, so kilograms to pounds and pounds to kilograms are the same tool used in either direction.
- Choose your units from the grouped list: metric, imperial and US, or the precious-metal units at the bottom.
- Read the result, the formula it used, and the two-way chart underneath — handy when you need a whole row of values rather than one number.
- Copy the result with one click, or share the URL, which encodes the unit pair you chose.
Reading UK, US and metric body weight
Body weight is where the three systems collide most often. The UK quotes stone and pounds ("11 st 4"), the US quotes pounds alone ("158 lb"), and almost everywhere else quotes kilograms. A stone is exactly 14 pounds, so 11 st 4 lb is 158 lb is 71.7 kg. Note that the converter treats stone as a decimal unit: 11.5 st means eleven and a half stone, which is 11 st 7 lb, not 11 st 5 lb.
For recipes, shipping and gym plates the useful anchors are that 1 kg is about 2.2 lb, a 20 kg plate is 44 lb, and a US 45 lb plate is 20.4 kg — close enough that they are usually treated as the same thing even though they are not.
Which factors are exact
The pound has been defined as exactly 0.45359237 kilograms since the 1959 international yard and pound agreement. Everything imperial follows from it without any rounding: an ounce is exactly one sixteenth of that, a stone exactly fourteen pounds, a US short ton exactly two thousand pounds and a UK long ton exactly 2,240. The metric tonne is exactly 1,000 kg.
The one genuinely different unit here is the troy ounce, at 31.1034768 g. It is used only for gold, silver and platinum. Quoting a gold price per "ounce" while using the everyday 28.35 g ounce understates the metal by just under 10 %, which is a costly rounding error.
Reference: common weights
| Kilograms | Pounds | Stone and pounds |
|---|---|---|
| 50 kg | 110.2 lb | 7 st 12 lb |
| 60 kg | 132.3 lb | 9 st 6 lb |
| 70 kg | 154.3 lb | 11 st 0 lb |
| 80 kg | 176.4 lb | 12 st 8 lb |
| 90 kg | 198.4 lb | 14 st 2 lb |
| 100 kg | 220.5 lb | 15 st 10 lb |
Mass, weight and why the difference rarely matters
Physics draws a hard line: mass is how much matter something contains and is measured in kilograms; weight is the force gravity exerts on that mass and is properly measured in newtons. A 70 kg person weighs about 687 N on Earth and about 114 N on the Moon, while their mass is 70 kg in both places.
In practice, every scale you will ever use is calibrated for Earth's gravity and reports mass, and every unit on this page — kilogram, pound, ounce, stone, ton — is a mass unit. So "weight converter" is the phrase everyone searches for, and the numbers it gives are the ones you want.
Questions
How many pounds are in a kilogram?
2.2046226218 lb. The pound is defined as exactly 0.45359237 kg, so the reverse direction — pounds to kilograms — is the exact one.
What is the difference between a US ton, a UK ton and a tonne?
A short (US) ton is 2,000 lb = 907.18 kg, a long (UK) ton is 2,240 lb = 1,016.05 kg, and a metric tonne is exactly 1,000 kg. All three are in the list.
Why is a troy ounce different from a normal ounce?
A troy ounce (31.103 g) is used only for precious metals; the everyday avoirdupois ounce is 28.35 g. Quoting gold in the wrong one overstates it by about 10 %.
Is weight the same as mass?
Strictly no — mass is the amount of matter and weight is the force gravity puts on it. Everyday use treats them as the same thing, and every unit here is a mass unit.