Quick answer: To convert grams to ounces, divide by 28.35 (or multiply by 0.03527). One ounce is exactly 28.349523125 g, so 100 g is 3.53 oz, 250 g is 8.82 oz and 454 g is almost exactly 1 lb (16 oz). These are UK avoirdupois ounces, the ones used for food and everyday weights.
British packaging has been in grams for decades, but plenty of family recipes, older cookbooks and market stalls still think in ounces. This page gives you a converter, the formula, a printable chart and a quick guide to the three different “ounces” you might meet. For the bigger picture, see our weight conversions hub.
Grams to ounces converter
g= oz ()How many ounces are in 100 grams?
100 grams is 3.53 ounces. Going the other way, one ounce is 28.35 g, so the rounded 25 g that many recipe conversions use for an ounce is slightly light. Ten grams is about a third of an ounce (0.35 oz), and one kilogram is 35.27 oz, or 2 lb 3.3 oz.
What is the formula for grams to ounces?
Ounces = grams ÷ 28.349523125. Multiplying by 0.035274 gives the same answer. The factor is exact because UK law defines the pound as 0.45359237 kg and the ounce as one-sixteenth of a pound.
A worked UK example: a standard block of butter in British supermarkets is 250 g. Divide by 28.35 and you get 8.82 oz. An old recipe asking for “8 oz butter” therefore needs 227 g, about 23 g less than the whole block. Cut off roughly a tenth and you are there.
To convert ounces back into grams, multiply by 28.35 instead. For bigger units, our explainer on how many pounds are in a stone shows how ounces, pounds and stones fit together, and the cooking converter handles spoons and cups.
Grams to ounces chart
Ounces are rounded to two decimal places. The right-hand column gives the nearest tenth, which is about as fine as a kitchen scale can read in ounces.
| Grams | Ounces | To nearest 0.1 oz | Grams | Ounces | To nearest 0.1 oz |
|---|---|---|---|---|---|
| 5 g | 0.18 oz | 0.2 oz | 125 g | 4.41 oz | 4.4 oz |
| 10 g | 0.35 oz | 0.4 oz | 150 g | 5.29 oz | 5.3 oz |
| 20 g | 0.71 oz | 0.7 oz | 175 g | 6.17 oz | 6.2 oz |
| 25 g | 0.88 oz | 0.9 oz | 200 g | 7.05 oz | 7.1 oz |
| 30 g | 1.06 oz | 1.1 oz | 225 g | 7.94 oz | 7.9 oz |
| 40 g | 1.41 oz | 1.4 oz | 250 g | 8.82 oz | 8.8 oz |
| 50 g | 1.76 oz | 1.8 oz | 300 g | 10.58 oz | 10.6 oz |
| 60 g | 2.12 oz | 2.1 oz | 350 g | 12.35 oz | 12.3 oz |
| 75 g | 2.65 oz | 2.6 oz | 400 g | 14.11 oz | 14.1 oz |
| 80 g | 2.82 oz | 2.8 oz | 450 g | 15.87 oz | 15.9 oz |
| 100 g | 3.53 oz | 3.5 oz | 500 g | 17.64 oz | 17.6 oz |
For heavier amounts it is easier to think in pounds and ounces. 500 g is 1 lb 1.6 oz, 750 g is 1 lb 10.5 oz, 1 kg is 2 lb 3.3 oz, 1.5 kg is 3 lb 4.9 oz and 2 kg is 4 lb 6.5 oz. The kg to lb converter handles anything larger.
Which ounce does the UK use?
For food and everyday weights, the UK uses the avoirdupois ounce of 28.35 g. Two other ounces cause confusion:
| Ounce | Measures | Metric value | Where it is used |
|---|---|---|---|
| Avoirdupois ounce (oz) | Weight | 28.35 g | Food, recipes, everyday weights |
| Troy ounce (oz t) | Weight | 31.10 g | Gold, silver and other precious metals |
| Imperial fluid ounce (fl oz) | Volume | 28.41 ml | Older UK recipes and drinks measures |
A troy ounce is about 10% heavier than a kitchen ounce, so never use a food conversion for a bullion price. The imperial fluid ounce is a volume, but it was designed so that a fluid ounce of water weighs about one ounce: 28.41 ml of water weighs roughly 28.4 g. That coincidence only holds for water and liquids of similar density, not for oil, honey or flour.
Why do UK packs show grams instead of ounces?
Because UK law requires metric units as the primary indication for goods sold by weight. An ounce figure may appear alongside, but it must not be more prominent than the metric one. The government confirmed this position in its December 2023 response to the “Choice on units of measurement” consultation, choosing not to change the law on imperial markings.
That is why you will see “454 g” on a pack that was once called a pound, and why loose goods are priced per kilogram. The weight converter covers every combination if you need to compare an old recipe with modern pack sizes.
Frequently asked questions
How many grams are in an ounce?
One avoirdupois ounce is exactly 28.349523125 g, usually rounded to 28.35 g.
What is 200 grams in ounces?
200 g is 7.05 oz, just over 7 ounces.
Is a UK ounce different from a US ounce?
No. The weight ounce is the same 28.35 g in both countries. Only the fluid ounce differs: 28.41 ml in the UK and 29.57 ml in the US.
How many grams is a quarter pound?
A quarter pound is 4 oz, which is 113.4 g.
Can I sell goods in ounces in the UK?
Goods sold by weight must be marked in metric units. You may show ounces alongside, as long as the imperial figure is not more prominent than the metric one.
Sources
- Weights and Measures Act 1985 (legislation.gov.uk): definition of the pound and its subdivisions.
- GOV.UK: Choice on units of measurement, consultation response (December 2023).
- NIST: unit conversion (avoirdupois, troy and fluid ounces).