To convert milliliters to fluid ounces (mL to fl oz), multiply by 0.033814. 1 milliliter equals 0.033814 fl oz, about 20% of a teaspoon.
| milliliters | fluid ounces |
|---|---|
| 1 milliliter | 0.033814 fl oz |
| 2 milliliters | 0.067628 fl oz |
| 5 milliliters | 0.16907 fl oz |
| 10 milliliters | 0.33814 fl oz |
| 25 milliliters | 0.84535 fl oz |
| 50 milliliters | 1.6907011 fl oz |
| 100 milliliters | 3.3814023 fl oz |
| 250 milliliters | 8.4535057 fl oz |
| 500 milliliters | 16.907011 fl oz |
| 1000 milliliters | 33.814023 fl oz |
The factor is 0.0338140, which is derived rather than defined, so any decimal you see has been rounded somewhere.
No simple round multiplier is close enough to be useful, so this is one to look up rather than estimate. The exact factor is 0.0338140.
Going the other way, one fluid ounce is 29.574 mL, which is usually the easier direction to work in. Because the forward factor is small, watch the decimal place rather than the digits: a factor-of-ten slip is the common error, not a rounding one.
To anchor the scale: 50 milliliters is about 1.69 fl oz.