Fluid Ounces to Milliliters
Result:
Enter a volume to convert.
Convert U.S. fluid ounces to milliliters. From is set to fluid ounces and To is set to milliliters. The result updates as you type. One U.S. fluid ounce is exactly 29.5735295625 milliliters. Liters, cups, and gallons are on the volume converter. That converter does not list fluid ounces. The other direction is milliliters to fluid ounces.
Fluid ounces to milliliters formula
NIST Handbook 44 (2024), Appendix C defines the U.S. gallon as 231 cubic inches, equal to 3.785411784 liters. A U.S. fluid ounce is 1/128 of that gallon. Eight of those ounces are the U.S. cup of 236.5882365 milliliters.
1 fl oz = 3.785411784 ÷ 128 L = 29.5735295625 mL exactly.
Formula: milliliters = fluid ounces × 29.5735295625.
The converter multiplies by the exact gallon and divides by 128, then rounds the displayed result to five decimal places. The figure 29.57353 mL is that rounding, not a different ounce. This page does not use the British fluid ounce.
Example: 1 fl oz shows 29.57353 mL. 8 fl oz show 236.58824 mL, one cup.
Fluid ounces to milliliters reference table
Each value below is the converter result at five decimal places. Enter the same fluid ounces in the form above and the result should match. Eight fluid ounces are one cup, and 128 fluid ounces are one gallon.
| U.S. fluid ounces | Milliliters |
|---|---|
| 0.5 | 14.78676 |
| 1 | 29.57353 |
| 2 | 59.14706 |
| 4 | 118.29412 |
| 6 | 177.44118 |
| 8 | 236.58824 |
| 12 | 354.88235 |
| 16 | 473.17647 |
| 32 | 946.35295 |
| 64 | 1892.70589 |
| 128 | 3785.41178 |
Fluid ounces to milliliters examples
One ounce: 1 fl oz displays as 29.57353 mL. The exact value is 29.5735295625 mL.
A cup: 8 fl oz are one U.S. cup and display as 236.58824 mL. The cups to milliliters page shows the same milliliters for 1 cup.
A can and a gallon: 12 fl oz display as 354.88235 mL. 128 fl oz display as 3785.41178 mL, one U.S. gallon.
Quick mental math (approximation)
To estimate milliliters, multiply the fluid ounces by 30. Example: 1 fl oz × 30 is about 30 mL. The exact result is 29.57353 mL.
This shortcut is an approximation. It runs about 1.4 percent high. Use the converter or the exact formula for recipes, labels, or records.
Fluid ounces to milliliters FAQ
How many milliliters are in a fluid ounce?
One U.S. fluid ounce is exactly 29.5735295625 milliliters. The converter shows 29.57353 mL. That displayed figure is rounding, not a second definition.
How many fluid ounces are in a cup?
Eight U.S. fluid ounces are one U.S. cup. Eight fluid ounces display as 236.58824 mL and as 1.00000 cup.
How do I convert milliliters to fluid ounces?
Divide milliliters by 29.5735295625. Example: 30 mL shows 1.01442 fl oz.