Convert grams (g) to fluid ounces (fl oz) by dividing the grams by the substance's density (in g/mL) and then dividing by 29.5735. The formula is: Fluid Ounces = Grams ÷ (Density × 29.5735). For water (density = 1.0 g/mL), divide grams by 29.5735.
Grams measure mass (weight) and fluid ounces measure volume (space). A direct 1-to-1 conversion between mass and volume is only possible when the density of the substance is known.
The Grams to Fluid Ounces Conversion Formula
To convert grams to US fluid ounces, use the following 2-step formula:
Step 1: Volume (mL) = Grams ÷ Density (g/mL) Step 2: Fluid Ounces = Volume (mL) ÷ 29.5735 Combine both steps into a single formula:
Fluid Ounces = Grams ÷ (Density × 29.5735) Use 28.4131 instead of 29.5735 for UK (Imperial) fluid ounces. 1 US fl oz = 29.5735 mL (milliliters). 1 UK fl oz = 28.4131 mL.
Density Values for 8 Common Substances
There are 8 substances most frequently converted from grams to fluid ounces in cooking, baking, and nutrition. The table below lists the density value needed for each conversion.
| Substance | Density (g/mL) | 1 g = ? US fl oz | 100 g = ? US fl oz |
|---|---|---|---|
| Water | 1.00 | 0.0338 fl oz | 3.38 fl oz |
| Whole Milk | 1.03 | 0.0328 fl oz | 3.28 fl oz |
| Heavy Cream | 0.994 | 0.0340 fl oz | 3.40 fl oz |
| Vegetable Oil | 0.92 | 0.0368 fl oz | 3.68 fl oz |
| Olive Oil | 0.91 | 0.0372 fl oz | 3.72 fl oz |
| All-Purpose Flour | 0.529 | 0.0639 fl oz | 6.39 fl oz |
| Granulated Sugar | 0.845 | 0.0400 fl oz | 4.00 fl oz |
| Honey | 1.42 | 0.0238 fl oz | 2.38 fl oz |
100 grams of flour equals 6.39 fl oz, while 100 grams of honey equals 2.38 fl oz — a 168% difference in volume for the same weight. Density determines the conversion result.
5 Worked Examples: Grams to Fluid Ounces
Example 1: 250 Grams of Water to Fluid Ounces
- Density of water: 1.0 g/mL
- Volume: 250 g ÷ 1.0 = 250 mL
- Fluid ounces: 250 ÷ 29.5735 = 8.45 fl oz
250 grams (0.25 kg or 0.551 lb) of water = 8.45 US fluid ounces.
Example 2: 150 Grams of Milk to Fluid Ounces
- Density of whole milk: 1.03 g/mL
- Volume: 150 g ÷ 1.03 = 145.63 mL
- Fluid ounces: 145.63 ÷ 29.5735 = 4.92 fl oz
150 grams of whole milk = 4.92 US fluid ounces.
Example 3: 200 Grams of Vegetable Oil to Fluid Ounces
- Density of vegetable oil: 0.92 g/mL
- Volume: 200 g ÷ 0.92 = 217.39 mL
- Fluid ounces: 217.39 ÷ 29.5735 = 7.35 fl oz
200 grams (0.2 kg or 0.441 lb) of vegetable oil = 7.35 US fluid ounces.
Example 4: 500 Grams of All-Purpose Flour to Fluid Ounces
- Density of all-purpose flour: 0.529 g/mL
- Volume: 500 g ÷ 0.529 = 945.18 mL
- Fluid ounces: 945.18 ÷ 29.5735 = 31.96 fl oz
500 grams (0.5 kg or 1.102 lb) of all-purpose flour = 31.96 US fluid ounces.
Example 5: 340 Grams of Honey to Fluid Ounces
- Density of honey: 1.42 g/mL
- Volume: 340 g ÷ 1.42 = 239.44 mL
- Fluid ounces: 239.44 ÷ 29.5735 = 8.10 fl oz
340 grams (0.34 kg or 0.750 lb) of honey = 8.10 US fluid ounces.
Quick Reference: Grams to Fluid Ounces for Water
The following table provides pre-calculated conversions for 12 common gram amounts of water (density = 1.0 g/mL).
| Grams (g) | US Fluid Ounces | UK Fluid Ounces | Milliliters (mL) |
|---|---|---|---|
| 1 g | 0.0338 fl oz | 0.0352 fl oz | 1 mL |
| 5 g | 0.1691 fl oz | 0.1760 fl oz | 5 mL |
| 10 g | 0.3381 fl oz | 0.3520 fl oz | 10 mL |
| 25 g | 0.8454 fl oz | 0.8799 fl oz | 25 mL |
| 50 g | 1.6907 fl oz | 1.7598 fl oz | 50 mL |
| 100 g | 3.3814 fl oz | 3.5195 fl oz | 100 mL |
| 150 g | 5.0721 fl oz | 5.2793 fl oz | 150 mL |
| 200 g | 6.7628 fl oz | 7.0390 fl oz | 200 mL |
| 250 g | 8.4535 fl oz | 8.7988 fl oz | 250 mL |
| 500 g | 16.9070 fl oz | 17.5975 fl oz | 500 mL |
| 750 g | 25.3605 fl oz | 26.3963 fl oz | 750 mL |
| 1000 g | 33.8140 fl oz | 35.1951 fl oz | 1000 mL |
3 Common Mistakes When Converting Grams to Fluid Ounces
There are 3 common mistakes that cause incorrect grams to fluid ounces conversions:
- Ignoring density — Dividing grams by 29.5735 only works for water. For every other substance, the density value is required. Skipping density produces errors between 3% and 90% depending on the substance.
- Mixing up US and UK fluid ounces — 1 US fl oz (29.5735 mL) is 4.1% larger than 1 UK fl oz (28.4131 mL). Check the measurement system in your recipe before converting.
- Confusing fluid ounces with weight ounces — Fluid ounces (fl oz) measure volume. Weight ounces (oz) measure mass. 1 fl oz of water weighs 1.043 weight ounces, not 1.0. These are 2 different units with different purposes.
Frequently Asked Questions
How do I convert grams to fluid ounces?
Divide the grams by the substance's density (g/mL), then divide by 29.5735 to get US fluid ounces. For water (density = 1.0 g/mL), divide grams directly by 29.5735. For milk (density = 1.03 g/mL), divide grams by 1.03 first, then divide by 29.5735.
How many fluid ounces are in 100 grams?
100 grams of water equals 3.3814 US fluid ounces (fl oz). For other substances: 100 g of milk = 3.28 fl oz, 100 g of vegetable oil = 3.68 fl oz, 100 g of flour = 6.39 fl oz, and 100 g of honey = 2.38 fl oz. The volume depends on the density of each substance.
Can I convert grams to fluid ounces without knowing the density?
Only for water. Water has a density of 1.0 g/mL, so grams ÷ 29.5735 = US fl oz. For all other substances, the density value is required to get an accurate conversion because grams measure mass and fluid ounces measure volume.
Use the grams to fluid ounces converter for instant calculations with built-in density values for water, milk, oil, flour, sugar, butter, and honey.