This converter turns US fluid ounces into US cups instantly, using the exact factor 1 US fluid ounce = 0.125 US cups. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
One eighth of a US cup, roughly 29.57 millilitres. The US legal cup used in recipes: 240 mL, or 236.6 mL by the customary definition.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
US fluid ounces- The amount you are converting, measured in US fluid ounces
0.125- The exact number of US cups in one US fluid ounce
US cups- The converted result
How it works, step by step
- Enter the number of US fluid ounces you want to convert.
- The value is multiplied by 0.125, the exact conversion factor.
- The result is displayed in US cups, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 US fluid ounces
Multiply 5 by 0.125. That gives 0.625 US cups. A quick sanity check: one US fluid ounce is smaller than one US cup, so the number should get smaller — and it does.
Converting 72 US fluid ounces
72 × 0.125 = 9 US cups. Working backwards, 9 ÷ 0.125 returns 72 US fluid ounces, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many US cups are in one US fluid ounce?
Exactly 0.125. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert US fluid ounces to US cups?
Us Cups = US fluid ounces × 0.125. To reverse it, divide instead: US fluid ounces = US cups ÷ 0.125, which is the same as multiplying by 8.
Is the US fluid ounce bigger than the US cup?
No. One US fluid ounce is only 0.125 of a US cup, so the US cup is the larger unit.
Why does my answer differ slightly from other us-fluid-ounces to cups converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a US fluid ounce?
One eighth of a US cup, roughly 29.57 millilitres.
What is a US cup?
The US legal cup used in recipes: 240 mL, or 236.6 mL by the customary definition.
Us Fluid Ounces to US cups reference table
| Us Fluid Ounces | Us Cups |
|---|---|
| 0.5 fl oz | 0.0625 cup |
| 1 fl oz | 0.125 cup |
| 2 fl oz | 0.25 cup |
| 3 fl oz | 0.375 cup |
| 5 fl oz | 0.625 cup |
| 10 fl oz | 1.25 cup |
| 15 fl oz | 1.875 cup |
| 20 fl oz | 2.5 cup |
| 25 fl oz | 3.125 cup |
| 50 fl oz | 6.25 cup |
| 75 fl oz | 9.375 cup |
| 100 fl oz | 12.5 cup |
| 250 fl oz | 31.25 cup |
| 500 fl oz | 62.5 cup |
| 1000 fl oz | 125 cup |
Exact factor: 1 US fluid ounce = 0.125 US cups. Values rounded for display.