How Much Is 1 Fluid Ounce of Water in Ounces?
1 fluid ounce of water weighs 1.04 oz. This is based on water having a density of 236.59g per cup. Because fluid ounces measure volume and ounces measure weight, the result depends on the ingredient, and a different ingredient would give a different result for the same 1 fluid ounce.
Formula and Step-by-Step
- Start with 1 fluid ounce of water
- 1 fluid ounce of water = 29.57g
- 1 × 29.57 = 29.57g
- Convert grams to ounces: 29.57 ÷ 28.3495 = 1.04 oz
The same formula works for any amount. Multiply (or divide) by the density, then convert units as needed.
Measuring Tip
For liquids, place your measuring cup on a flat surface and read at eye level. The bottom of the meniscus (the curve at the surface) should align with the measurement line.
Water at Different Amounts
How water scales across common fluid ounces measurements. Your amount (1 fluid ounce) is highlighted.
For reference, 1 fluid ounce of water (29.57g) is close in weight to a slice of bread (30g).
Other Amounts of Water
| Fluid Ounces | US Ounces | UK Fluid Ounce |
|---|---|---|
| 1 fluid ounce | 1.04 oz | 1.00 oz |
| 2 fluid ounces | 2.09 oz | 2.00 oz |
| 3 fluid ounces | 3.13 oz | 3.01 oz |
| 4 fluid ounces | 4.17 oz | 4.01 oz |
| 5 fluid ounces | 5.22 oz | 5.01 oz |
| 6 fluid ounces | 6.26 oz | 6.01 oz |
| 8 fluid ounces | 8.35 oz | 8.02 oz |
| 10 fluid ounces | 10.43 oz | 10.02 oz |
| 12 fluid ounces | 12.52 oz | 12.03 oz |
| 16 fluid ounces | 16.69 oz | 16.04 oz |
Understanding the Units
What is a Fluid Ounce?
A US fluid ounce (fl oz) is a unit of volume equal to 29.574 milliliters or 1/8 of a cup. It measures liquid volume and should not be confused with the ounce (oz), which measures weight.
What is an Ounce?
An ounce (oz) is a US customary unit of weight equal to 28.3495 grams or 1/16 of a pound. In cooking, "ounces" refers to weight (avoirdupois ounces), not fluid ounces which measure volume.