The exact factor, and a shortcut you can do in your head
One avoirdupois ounce is defined as exactly 28.349523 grams, so one kilogram is 35.274 ounces. For a fast estimate, multiply the kilograms by 35: 5 kg → 175 oz, within a fraction of the exact 176.37. The remaining 0.78% only matters when money or shipping weight is on the line.
Quick reference (avoirdupois ounces)
| Kilograms | Ounces | Pounds & ounces |
|---|---|---|
| 0.25 kg | 8.82 oz | 0 lb 8.8 oz |
| 0.5 kg | 17.64 oz | 1 lb 1.6 oz |
| 1 kg | 35.27 oz | 2 lb 3.3 oz |
| 2 kg | 70.55 oz | 4 lb 6.5 oz |
| 5 kg | 176.37 oz | 11 lb 0.4 oz |
| 10 kg | 352.74 oz | 22 lb 0.7 oz |
These are ounces of weight. A fluid ounce (fl oz) measures volume and does not convert to kilograms — different kind of quantity entirely.
Two ounces that aren't the same size
Most conversions use the avoirdupois ounce (food, parcels, general weight). Precious metals are sold in troy ounces, which are about 10% heavier — use the wrong one and a gold weight is off by that much.
A troy ounce is 9.7% heavier than an everyday ounce, so 1 kg is 35.274 avoirdupois ounces but only 32.151 troy ounces.
The troy pound paradox
- Troy ounce heavier, troy pound lighter. A troy ounce beats a regular ounce, yet a troy pound (12 troy oz = 373 g) is lighter than a regular pound (16 oz = 454 g).
- Which to pick. Gold, silver and jewellery use troy; everything else — food, shipping, body weight — uses avoirdupois.
Common questions
How many ounces are in a kilogram?
One kilogram is 35.274 ounces (avoirdupois, the everyday ounce). The value comes from the 1959 agreement fixing one ounce at 28.349523 grams.
How do I convert kg to ounces in my head?
Multiply the kilograms by 35. For 2 kg that is 70 oz, against the exact 70.55 — close enough for cooking, but use the full figure for trade or shipping.
What is the difference between an ounce and a troy ounce?
A standard (avoirdupois) ounce is 28.35 g and is used for food and shipping. A troy ounce is 31.10 g, about 10% heavier, and is used for gold and silver. So 1 kg is 35.274 regular ounces but only 32.151 troy ounces.
