Grams to Ounces: The Cook's Conversion Guide
Convert grams to ounces using the exact 1 oz = 28.3495 g ratio, with a kitchen-focused reference table and the history of the ounce.
Grams to ounces is the everyday small-mass conversion — the one you meet in recipes, food packaging, coffee dosing, and shipping. Unlike volume, the mass conversion is unambiguous: there's only one ounce that matters for food and general use, and its value is defined exactly.
The formula
ounces = grams ÷ 28.3495 grams = ounces × 28.3495
Precisely, 1 oz (avoirdupois) = 28.349523125 g exactly, derived from the 1959 international yard and pound agreement, which fixed the pound at 0.45359237 kg. The ounce is one-sixteenth of that pound.
*Example:* a chicken breast weighs 200 g. 200 ÷ 28.3495 = 7.05 oz — a bit under a US "half pound" (8 oz).
Kitchen reference table
| Grams | Ounces | Kitchen context |
|---|---|---|
| 15 g | 0.53 oz | 1 tablespoon of flour |
| 28 g | 1.00 oz | Dark chocolate square |
| 50 g | 1.76 oz | Small egg |
| 100 g | 3.53 oz | Standard bar of chocolate |
| 150 g | 5.29 oz | Cup of flour (approx.) |
| 227 g | 8.00 oz | US "half pound" |
| 250 g | 8.82 oz | 1 metric cup of butter |
| 454 g | 16.00 oz | 1 US pound |
| 500 g | 17.64 oz | Half-kilo pack of pasta |
For any specific quantity, the Grams to Ounces converter is faster (and less error-prone) than mental math on the 28.35 ratio.
Three different ounces — only one matters here
For general and food use, "ounce" always means the avoirdupois ounce (28.3495 g). Two rarer variants still exist:
- Troy ounce (31.1035 g) — used only for precious metals and gemstones. If gold is quoted at "$2,100 per ounce", that's a troy ounce, not the kitchen one. See Wikipedia on troy weight.
- Apothecaries' ounce (also 31.1035 g) — historical, used in pre-metric pharmacy. Obsolete in modern medicine.
If you're weighing food, mail, a pet, or anything you'd find in a supermarket, use the avoirdupois value.
Why the ratio isn't a round number
Both the gram and the ounce came from very different traditions. The gram is one-thousandth of a kilogram, which was originally defined in 1795 as the mass of one cubic centimetre of water at maximum density, and today is defined through Planck's constant. The ounce descends via the Roman *uncia* — one-twelfth of a *libra* — through a chain of medieval English redefinitions. The 1959 treaty locked the two systems together at 1 lb = 0.45359237 kg, which propagates to 1 oz = 28.349523125 g.
Everyday cooking conversions
For recipe writing:
- Butter and cheese. US recipes often quote "1 stick" (½ cup, 4 oz, 113 g).
- Flour and sugar. Weights vary by ingredient density, but roughly 1 cup flour ≈ 125 g, 1 cup sugar ≈ 200 g. Ounce weights on package labels are always avoirdupois.
- Coffee. Third-wave coffee culture is metric worldwide — a "typical espresso dose" is 18 g dry, 36 g wet.
For fluid conversions, don't mix grams with fluid ounces — they measure different things. Use the Ml to Fl Oz converter for liquid volumes.
FAQ
How many grams is 1 ounce? Exactly 28.349523125 g. For quick mental math, "28.35 g" is close enough for most kitchen use.
Is 100 g the same as a quarter pound? Nearly. 100 g = 3.53 oz; a quarter pound = 4 oz = 113.4 g. The gap is about 13%, enough to matter for a burger patty.
Why does gold use a different ounce? Gold, silver, and platinum have been traded in troy ounces since medieval European fairs, and the convention stuck. A troy ounce is about 10% heavier than an avoirdupois ounce, which is worth noting when comparing bullion prices.
---
*For any weight in between, the free Grams to Ounces Converter uses the full 28.349523125 g/oz definition — no rounding shortcuts.*