Ounces to Grams
Convert ounces to grams for metric recipes, nutrition, and lab use. Enter any oz value — get grams with context for food portions, precious metals, and scientific measurement.
Enter your values above to see the results.
Tips & Notes
- ✓Quick estimate: multiply oz by 28 for approximate grams (1.6% low). For more accuracy, multiply by 28.35. Exact value: 28.3495 g/oz. Example: 4 oz → 4 × 28.35 ≈ 113.4 g (exact: 113.398 g).
- ✓Food portion sizes in grams: 1 oz protein serving (meat/fish) = 28.35 g. 3 oz cooked chicken breast (typical serving) = 85.05 g ≈ 85 g. 8 oz steak = 226.8 g. 16 oz (1 lb) whole chicken breast = 453.6 g.
- ✓US nutrition labels list daily values based on a 2,000-calorie diet with serving sizes in oz. Converting to grams helps when comparing with international food databases (which use grams). USDA Food Data Central uses grams for all nutrient data.
- ✓Laboratory measurements: analytical balances measure in grams; US lab protocols sometimes specify amounts in ounces for legacy reasons. 1 oz of reagent = 28.3495 g. For pharmaceutical compounding, always verify units — pharmacies use grams exclusively for drug compounds.
- ✓Shipping: USPS, UPS, and FedEx US domestic rates use oz below 16 oz and lbs above. A package weighing 6 oz = 170.1 g; 12 oz = 340.2 g; 15 oz = 425.2 g. Just above 16 oz threshold switches to 1-lb pricing — weigh carefully near the threshold.
Common Mistakes
- ✗Using troy oz factor (31.1035 g) for food — food, postal, and retail ounces are avoirdupois (28.3495 g). Troy oz are only for precious metals. Using the troy factor for cooking overstates ingredient weight by 9.7%.
- ✗Confusing fluid ounces with weight ounces — 1 fluid oz is a volume unit (≈29.574 ml), not a weight unit. A recipe calling for 4 fl oz of milk means 118.3 ml (volume), not 4 × 28.35 = 113.4 g (though for water/milk these are close due to similar density).
- ✗Applying oz-to-g linearly to oz-per-unit products — "16 oz jar" means the net weight of content is 16 oz = 453.6 g. It does NOT mean 16 fluid oz of liquid. Verify whether a jar is labeled by weight (oz) or volume (fl oz).
- ✗Rounding 28.3495 to 28 for repeated calculations — converting a full recipe with 12 different ingredients, each rounded to 28 instead of 28.35, introduces errors that compound. Use the exact factor for recipe development or professional food production.
- ✗Forgetting the 16-oz-to-1-lb relationship — 16 oz = 1 lb = 453.592 g. If a US recipe calls for 1.5 lbs = 24 oz = 680.4 g. Mixing lbs and oz in mental math often causes factor-of-16 errors (treating 1 lb as if it were 10 oz, for example).
Ounces to Grams Overview
Ounces are the US everyday unit for food weight, postal measurements, and retail product sizing. Converting to grams enables comparison with international nutrition databases, following metric recipes precisely, and communicating food quantities in scientific or international medical contexts.
Ounces to grams formula:
g = oz × 28.3495 | 1 oz (avoirdupois) = 28.3495 g | Troy oz (gold/silver) = 31.1035 g
EX: US recipe: 8 oz butter → 8 × 28.3495 = 226.8 g. 3 oz serving of meat → 3 × 28.3495 = 85.05 g ≈ 85 g. 1 troy oz gold at $1,900 → 1,900/31.1035 = $61.08 per gramInverse — grams to ounces:
oz = g ÷ 28.3495 | oz = g × 0.035274
EX: EU recipe: 300 g strawberries → 300/28.3495 = 10.58 oz. Lab sample 50 g → 50/28.3495 = 1.764 ozFood portions — ounces to grams:
| Ounces (oz) | Grams (g) | Common Food Portion |
|---|---|---|
| 1 oz | 28.35 g | Cheese slice, nut portion |
| 2 oz | 56.70 g | Small protein serving |
| 3 oz | 85.05 g | Standard meat/fish serving (USDA) |
| 4 oz | 113.40 g | Quarter-pound burger patty |
| 6 oz | 170.10 g | Standard chicken breast |
| 8 oz | 226.80 g | Half-pound steak |
| 12 oz | 340.19 g | Large steak, can of soda |
| 16 oz (1 lb) | 453.59 g | Standard pound package |
| Unit | Grams | Use | Example at $1,900/troy oz |
|---|---|---|---|
| 1 avoirdupois oz | 28.3495 g | Food, postal, retail | N/A for gold pricing |
| 1 troy ounce | 31.1035 g | Gold, silver, platinum | $1,900 = $61.08/g |
| 10 troy oz | 311.04 g | Standard gold bar (small) | $19,000 |
| 100 troy oz | 3,110.3 g | 100-oz silver bar | Variable |
| 400 troy oz | 12,441 g | London Good Delivery gold bar | ~$760,000 |
Frequently Asked Questions
Multiply ounces by 28.3495. Examples: 1 oz = 28.35 g; 2 oz = 56.70 g; 4 oz = 113.40 g; 8 oz (half pound) = 226.80 g; 12 oz = 340.19 g; 16 oz (1 lb) = 453.59 g; 32 oz (2 lbs) = 907.18 g. Quick estimate: multiply oz by 28 (within 1.6%). For baking: a 3.5-oz packet of yeast = 3.5 × 28.3495 = 99.2 g.
Standard US food portions: 1 oz cheese = 28.35 g (about a 1-inch cube); 3 oz cooked meat = 85 g (standard restaurant serving); 3.5 oz fish fillet = 99 g; 8 oz (half-pound) burger = 227 g before cooking; 12 oz steak = 340 g; 1 oz nuts = 28 g (about a small handful); 1 oz crackers = 28 g (about 5-6 crackers); 5 oz wine = 142 g; 12 oz beer = 340 g. The USDA defines a standard protein serving as 3 oz = 85 g of cooked lean meat, poultry, or seafood.
Multiply every oz measurement by 28.3495 (or 28.35 for quick work). Example: a cookie recipe calling for 8 oz butter (226.8 g), 6 oz sugar (170.1 g), 10 oz flour (283.5 g), 2 oz chocolate chips (56.7 g). Many bakers prefer gram measurements because kitchen scales are more precise than volume measures, and gram batches are easier to scale up or down. Baking ratios stay consistent: the ratio of 8 oz flour to 4 oz butter (2:1) becomes 226.8 g to 113.4 g — still exactly 2:1.
Precious metals (gold, silver, platinum) are always measured in troy ounces. 1 troy oz = 31.1035 g — about 10% heavier than the regular (avoirdupois) ounce of 28.3495 g. Gold price is quoted per troy oz. If gold is $1,900/troy oz, the price per gram = $1,900/31.1035 = $61.08/g. If you mistakenly used 28.3495 g/oz: price per gram would appear to be $67.04/g — 9.76% higher than actual. Always use 31.1035 g when working with precious metals pricing or when buying/selling gold and silver by the ounce.
US dietitians traditionally work in ounces and cups for patient communication but use grams for scientific calculation. The Dietary Reference Intakes (DRIs) specify nutrients in grams and milligrams: dietary fiber 25-38 g/day; protein 0.8 g/kg body weight; sodium less than 2,300 mg/day; calcium 1,000-1,200 mg/day. Converting for patient communication: 25 g fiber = 0.88 oz; 50 g protein = 1.76 oz. Food logs in apps like MyFitnessPal show grams; US restaurant menus show oz. Translating between them helps compare intake to recommendations.
In regulated cannabis markets, quantities are sold and tracked in both ounces (retail) and grams (cultivation, lab testing). Standard quantities: 1 gram = 0.035 oz; one-eighth (1/8 oz) = 3.5 g; one-quarter (1/4 oz) = 7.09 g; one-half (1/2 oz) = 14.17 g; one ounce = 28.35 g. State possession limits are typically expressed in both systems: 1 oz = 28.35 g. Lab testing of potency (THC%, CBD%) is based on mg per gram of dried flower. Herbal teas, spices, and supplements use the same gram-to-oz conversions as any other dry ingredient.