Volume conversion
18 fl oz to cups
2.25 cups
18 US fluid ounces = 2.25 US cups. Exact factor: cups = fl oz ÷ 8.
Live converter
Edit either field — the other updates instantly. Type decimal values like 38.4.
The formula
cups = fl oz ÷ 8
Worked example: 18 × 0.125 = 2.25 cups.
Values near 18 fl oz
| fl oz | cups |
|---|---|
| 15 | 1.875 |
| 16 | 2 |
| 17 | 2.125 |
| 18this page | 2.25 |
| 19 | 2.375 |
| 20 | 2.5 |
| 21 | 2.625 |
Frequently asked
How do you convert US fluid ounces to US cups?
Apply the formula cups = fl oz ÷ 8. Enter any value in the live converter above and the result updates as you type.
What is 18 fl oz in cups?
18 fl oz equals 2.25 cups. The reference table below shows the values immediately around 18 fl oz.
Is this conversion exact?
Yes. If a recipe gives ounces for a dry ingredient it usually means weight, not fluid ounces — check before pouring.