Ounces to Grams for Cooking
This calculator converts between ounces (oz) and grams (g) for cooking and baking, using the exact internationally recognized conversion factor of 1 oz = 28.3495 g (avoirdupois ounce). Whether you're scaling a recipe from a US cookbook to metric measurements or following a European pastry formula in a US kitchen, precise unit conversion is critical — especially in baking, where a 5–10 g difference in flour or sugar can noticeably change texture and structure. The calculator works in both directions: oz → g and g → oz, covering the most common ingredient weights used in professional and home cooking.
When to use this calculator
- Scaling a US recipe that calls for 4 oz of butter into grams for a kitchen with a metric digital scale
- Converting a French pastry recipe that specifies 250 g of bread flour into ounces for a US cook without a metric scale
- Portioning 16 oz (1 lb) of ground beef into individual 4 oz (113 g) burger patties with precision
- Measuring spice blends accurately when a rub recipe lists 0.5 oz of smoked paprika but your scale reads only in grams
- Comparing nutrition labels: a US label shows a serving size of 1 oz (28 g) of cheese, confirming the correct portion weight
Calculation example
- Typical value
- Result
How it works
3 min readHow It's Calculated
The conversion uses the avoirdupois ounce, the standard unit for food and commerce in the United States (defined by NIST):
# Ounces to Grams
grams = ounces × 28.3495231
# Grams to Ounces
ounces = grams ÷ 28.3495231
# Example: 6 oz of all-purpose flour
grams = 6 × 28.3495 = 170.10 g
# Example: 500 g of bread flour
ounces = 500 ÷ 28.3495 = 17.64 oz> ⚠️ Do not confuse with the troy ounce (31.1035 g), used for precious metals — never for food.
---
Reference Table
| Ounces (oz) | Grams (g) | Common Cooking Use |
|---|---|---|
| 0.25 oz | 7.09 g | Pinch of yeast packet |
| 0.5 oz | 14.17 g | Half a tablespoon of butter |
| 1 oz | 28.35 g | 1 serving size (cheese, deli meat) |
| 1.5 oz | 42.52 g | Standard shot of spirits |
| 2 oz | 56.70 g | Small chocolate square |
| 2.5 oz | 70.87 g | Typical egg (large) |
| 3.5 oz | 99.22 g | Small chicken breast |
| 4 oz | 113.40 g | ¼ lb burger patty |
| 6 oz | 170.10 g | 1 cup of all-purpose flour |
| 8 oz | 226.80 g | 1 cup of water / ½ lb |
| 12 oz | 340.19 g | Standard can of beer/soda |
| 16 oz | 453.59 g | 1 pound (1 lb) |
| 32 oz | 907.18 g | 2 pounds |
---
Typical Cases
Case 1: Baking bread — converting a US recipe to grams
A sourdough recipe calls for 12.3 oz of bread flour. Your kitchen scale only reads grams:
grams = 12.3 × 28.3495 = 348.7 gYou measure 349 g of bread flour — accurate enough for professional baking (±1 g tolerance).
Case 2: Converting a French recipe to ounces
A croissant dough recipe specifies 250 g of cold butter. Your scale reads in ounces:
ounces = 250 ÷ 28.3495 = 8.82 ozYou measure 8.8 oz of butter. Note: for laminated doughs, a ±2 g variance (≈0.07 oz) is acceptable.
Case 3: Portioning protein for meal prep
A nutrition plan calls for 4 oz cooked chicken breast per meal. You're cooking 7 portions:
Total = 7 × (4 × 28.3495) = 7 × 113.4 g = 793.8 g rawAccount for ~25% cooking weight loss → purchase ~1,058 g (≈37.3 oz ≈ 2.33 lb) raw chicken.
---
Common Mistakes
1. Using volume ounces (fl oz) for weight — 1 fl oz of water ≈ 29.57 g, but 1 fl oz of honey ≈ 42 g due to density differences. Always use weight ounces for dry and semi-solid ingredients.
2. Rounding too aggressively — Rounding 28.3495 to 28 introduces a 1.2% error. Over 10 oz, that's a 3.5 g shortfall — enough to affect cookie spread or bread hydration.
3. Confusing avoirdupois and troy ounces — The troy ounce (31.1035 g) appears on some antique kitchen scales. Using it for flour would mean 9.6% more ingredient than intended.
4. Assuming "1 cup = 8 oz by weight" — 1 cup of all-purpose flour weighs ~4.25 oz (120 g), not 8 oz. The 8 oz = 1 cup rule applies only to water and similar-density liquids.
5. Ignoring tare weight when using a bowl — Converting correctly but forgetting to zero/tare the scale before adding the ingredient negates the precision of the conversion entirely.
---
Related Calculators
Frequently asked questions
What is the exact conversion factor from ounces to grams?
The exact factor defined by NIST (the US National Institute of Standards and Technology) is 1 avoirdupois ounce = 28.349523125 grams, established under the international yard and pound agreement of 1959. For cooking purposes, rounding to 28.35 g is precise enough for virtually all recipes.
Is there a difference between a fluid ounce and a weight ounce in cooking?
Yes — and it's a critical distinction. A fluid ounce (fl oz) measures volume (≈29.57 mL), while a weight ounce measures mass (28.35 g). For water, they're close: 1 fl oz of water ≈ 29.57 g. But 1 fl oz of honey ≈ 42 g because honey is denser. Always check whether a recipe uses weight or volume ounces — US recipes often mix both.
How many grams is 1 oz of the most common baking ingredients?
All-purpose flour: 1 oz ≈ 28.35 g (but 1 cup ≈ 120–125 g, or ~4.4 oz). Granulated sugar: 1 oz ≈ 28.35 g. Butter: 1 oz ≈ 28.35 g (= 2 tablespoons). Salt: 1 oz ≈ 28.35 g. These weight-based conversions are consistent — unlike volume-based cup measurements, which vary by ingredient density and how the cup is filled.
Why do professional bakers prefer grams over ounces?
Grams offer finer resolution and easier scaling. A gram is roughly 1/28th of an ounce, so a metric scale can detect differences that an ounce-based scale misses entirely. Most professional kitchens and culinary schools in the US have shifted to grams because a 1 g error in a 500 g batch of bread dough (0.2% variance) has far less impact than a 1 oz error in the same batch (~5.6% variance).
How do I convert ounces to grams without a calculator?
Use the quick mental shortcut: multiply ounces by 28, then add 1% of that result. Example: 5 oz → 5 × 28 = 140, plus 1% of 140 (1.4) ≈ 141.4 g (exact: 141.75 g). The error is under 0.25%, acceptable for home cooking. For baking, always use a calculator or scale for precision.
Does the type of ingredient affect the ounce-to-gram conversion?
No — for weight measurements, 1 oz of any ingredient is always 28.35 g regardless of what it is. However, if a recipe uses volume ounces (cups, tablespoons), then density matters enormously. For example, 1 cup of water = 8 fl oz ≈ 237 mL ≈ 237 g, while 1 cup of bread flour = ~4.25 oz by weight ≈ 120 g.
What kitchen scale precision do I need for ounce/gram conversions?
For everyday cooking, a scale with 1 g / 0.1 oz resolution is sufficient. For professional baking or confectionery (chocolate tempering, macarons, bread hydration ratios), use a scale with 0.1 g resolution. The USDA recommends scales with at least 1 g precision for accurate portion control in food service. Scales accurate only to 5 g are inadequate for spice or leavener measurement.
How do ounce-to-gram conversions apply to nutrition labels?
The FDA requires US nutrition labels to list serving sizes in both household measures and metric (grams). A label showing '1 oz (28 g)' uses the standard avoirdupois conversion rounded to the nearest gram. When tracking macros or calories, use the gram value directly — it's more precise. For example, a 1 oz serving of almonds = 28 g = approximately 164 calories, 6 g protein, 14 g fat.