This converter turns US cups into imperial fluid ounces instantly, using the exact factor 1 US cup = 8.326741846 imperial fluid ounces. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The US legal cup used in recipes: 240 mL, or 236.6 mL by the customary definition. The UK fluid ounce, about 4% smaller than its US counterpart.
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 cups- The amount you are converting, measured in US cups
8.326741846- The exact number of imperial fluid ounces in one US cup
imperial fluid ounces- The converted result
How it works, step by step
- Enter the number of US cups you want to convert.
- The value is multiplied by 8.326741846, the exact conversion factor.
- The result is displayed in imperial fluid ounces, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 US cups
Multiply 5 by 8.3267418. That gives 41.6337 imperial fluid ounces. A quick sanity check: one US cup is larger than one imperial fluid ounce, so the number should get bigger — and it does.
Converting 72 US cups
72 × 8.3267418 = 599.5254 imperial fluid ounces. Working backwards, 599.5254 ÷ 8.3267418 returns 72 US cups, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many imperial fluid ounces are in one US cup?
Exactly 8.326741846. 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 cups to imperial fluid ounces?
Imperial Fluid Ounces = US cups × 8.326741846. To reverse it, divide instead: US cups = imperial fluid ounces ÷ 8.326741846, which is the same as multiplying by 0.1200949926.
Is the US cup bigger than the imperial fluid ounce?
Yes. One US cup equals 8.32674 imperial fluid ounces, so it is the larger unit.
Why does my answer differ slightly from other cups to imperial-fluid-ounces 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 cup?
The US legal cup used in recipes: 240 mL, or 236.6 mL by the customary definition.
What is a imperial fluid ounce?
The UK fluid ounce, about 4% smaller than its US counterpart.
Us Cups to imperial fluid ounces reference table
| Us Cups | Imperial Fluid Ounces |
|---|---|
| 0.5 cup | 4.1634 fl oz |
| 1 cup | 8.3267 fl oz |
| 2 cup | 16.6535 fl oz |
| 3 cup | 24.9802 fl oz |
| 5 cup | 41.6337 fl oz |
| 10 cup | 83.2674 fl oz |
| 15 cup | 124.9011 fl oz |
| 20 cup | 166.5348 fl oz |
| 25 cup | 208.1685 fl oz |
| 50 cup | 416.3371 fl oz |
| 75 cup | 624.5056 fl oz |
| 100 cup | 832.6742 fl oz |
| 250 cup | 2,081.69 fl oz |
| 500 cup | 4,163.37 fl oz |
| 1000 cup | 8,326.74 fl oz |
Exact factor: 1 US cup = 8.326741846 imperial fluid ounces. Values rounded for display.