Unit & Measurement Tables
Weight Conversion Table
Weight is where conversion errors do the most practical damage. A 5 lb luggage allowance read as 2.5 kg instead of 2.27 kg is a 230 g overage at the check-in desk; a 1 oz misread on a recipe is 28 g of flour. The tables below are built from the exact legal definition of the pound — 0.453 592 37 kilograms — so there is no accumulated rounding to blame.
Two conventions cause most of the confusion. First, the pound and the ounce here are the avoirdupois versions used for everything except precious metals and gemstones, which use troy ounces of 31.1035 g rather than 28.3495 g. Second, the stone is a British body-weight unit of exactly 14 lb; it never appears in US commerce, so a US reader seeing "11 st" should read it as 154 lb or 69.9 kg.
The kilogram is now defined by fixing the Planck constant rather than by a physical cylinder in Paris, but that change does not move any number in this table — the practical definition of the pound has been fixed since 1959 and remains exactly 0.453 592 37 kg.
Kilograms to pounds, ounces and stones
| Kilograms | Pounds | Ounces | Stones |
|---|---|---|---|
| 0.5 | 1.1 | 17.6 | 0.08 |
| 1 | 2.2 | 35.3 | 0.16 |
| 2 | 4.41 | 70.5 | 0.31 |
| 5 | 11.02 | 176.4 | 0.79 |
| 10 | 22.05 | 352.7 | 1.57 |
| 20 | 44.09 | 705.5 | 3.15 |
| 25 | 55.12 | 881.8 | 3.94 |
| 50 | 110.23 | 1,763.7 | 7.87 |
| 75 | 165.35 | 2,645.5 | 11.81 |
| 100 | 220.46 | 3,527.4 | 15.75 |
| 150 | 330.69 | 5,291.1 | 23.62 |
| 200 | 440.92 | 7,054.8 | 31.49 |
| 500 | 1,102.31 | 17,637 | 78.74 |
| 1,000 | 2,204.62 | 35,274 | 157.47 |
The pounds column is the one most people want; stones are included because body weight in the UK and Ireland is still quoted that way.
Pounds to kilograms and ounces
| Pounds | Kilograms | Ounces | Stones and pounds |
|---|---|---|---|
| 1 | 0.454 | 16 | 1 lb |
| 2 | 0.907 | 32 | 2 lb |
| 5 | 2.268 | 80 | 5 lb |
| 10 | 4.536 | 160 | 10 lb |
| 25 | 11.34 | 400 | 1 st 11 lb |
| 50 | 22.68 | 800 | 3 st 8 lb |
| 100 | 45.359 | 1,600 | 7 st 2 lb |
| 120 | 54.431 | 1,920 | 8 st 8 lb |
| 150 | 68.039 | 2,400 | 10 st 10 lb |
| 180 | 81.647 | 2,880 | 12 st 12 lb |
| 200 | 90.718 | 3,200 | 14 st 4 lb |
| 250 | 113.398 | 4,000 | 17 st 12 lb |
| 300 | 136.078 | 4,800 | 21 st 6 lb |
One stone is exactly 14 pounds, so the last column is division with a remainder, not a separate conversion.
Ounces to grams
| Ounces | Grams | Kilograms |
|---|---|---|
| 0.5 | 14.17 | 0.0142 |
| 1 | 28.35 | 0.0283 |
| 2 | 56.7 | 0.0567 |
| 4 | 113.4 | 0.1134 |
| 6 | 170.1 | 0.1701 |
| 8 | 226.8 | 0.2268 |
| 12 | 340.19 | 0.3402 |
| 16 | 453.59 | 0.4536 |
| 24 | 680.39 | 0.6804 |
| 32 | 907.18 | 0.9072 |
16 ounces make one pound, so the 16 oz row also reads 453.59 g — the definition of the pound.
How to Use These Tables
- Kilograms to pounds: multiply by 2.204 62. Pounds to kilograms: multiply by 0.453 592. These two factors are exact inverses of each other.
- For body weight in stones, divide pounds by 14 and keep the remainder. 168 lb is 12 st exactly; 172 lb is 12 st 4 lb.
- Ounces and pounds are the same system — 16 oz to the pound — so never mix a troy ounce into a grocery conversion.
- If you are converting a shipping weight, remember that carriers bill on whichever is greater, actual weight or dimensional weight, so a correct unit conversion can still give a surprise invoice.
Common Questions
How many pounds is 1 kg?
1 kg is 2.204 622 62 lb. The 2.2 figure most people use is 0.2% low, which is 0.2 kg on a 100 kg total — enough to matter for a checked bag but not for a recipe.
Is a pound heavier than 450 grams?
Yes. A pound is 453.592 37 g, so 450 g is about 3.6 g short. That gap is why a 450 g package and a 1 lb package are not interchangeable in a recipe that was written in the other system.
What is the difference between a short ton and a metric tonne?
A short ton is 2000 lb, or 907.185 kg. A metric tonne is 1000 kg, or 2204.62 lb. The metric tonne is about 10% heavier, which is why US industrial quotes and European quotes are not comparable without checking which one is meant.
Why does a stone have 14 pounds?
It is a historical wool-trade unit standardised in 14th-century England, kept alive for body weight. It has no relationship to the kilogram, so stone conversions always go through pounds.
How do I convert grams to ounces quickly?
Divide by 28.35. For a rough mental check, divide by 30 and add 6% back: 100 g ÷ 30 is 3.33, and 3.33 × 1.06 is 3.53 oz, which is correct to two decimals.
More Unit & Measurement Tables
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units — National Institute of Standards and Technology
- NIST Handbook 44 — Specifications, Tolerances and Other Technical Requirements — National Institute of Standards and Technology
- The International System of Units (SI Brochure), 9th edition — Bureau International des Poids et Mesures
Filed with Unit Conversion calculations.