ConvBolt — Unit ConverterUS cups to Fluid ounces Converter
Converting US cups to fluid ounces is a multiplication by a fixed factor: 1 cup = 8 fl oz. The table below covers the values people look up most often, and the formula section shows exactly where that factor comes from.
Because one us cup works out to 8 fl oz, the fluid ounce is the larger unit of the two: a figure given in fluid ounce always carries a larger number than the same measurement in us cup. A chart drawn in cup can hide that, so check which label the axis uses before you compare two readings.
When a container size is certified in fluid ounces but you are dosing in US cups, it pays to convert from the certified figure rather than from a rounded label.
The conversion factor used here is 8 fl oz per us cup (0 significant digits as shown). Kept to seven figures it covers professional measurement; if you round it to two or three decimals for a spreadsheet, the error scales with the input — at a value of 1,000 cup a factor rounded to three decimals can be off by a measurable amount. The reverse direction uses 0.125 cup per fl oz, the exact reciprocal, so a round trip through both pages returns your original number.
US cups to Fluid ounces formula
Use this formula to convert any us cup value to fluid ounces:
Worked example: 100 cup × 8 = 800 fl oz.
US cups to Fluid ounces conversion table
| US cups (cup) | Fluid ounces (fl oz) |
|---|---|
| 0.5 cup | 4 fl oz |
| 1 cup | 8 fl oz |
| 2 cup | 16 fl oz |
| 5 cup | 40 fl oz |
| 10 cup | 80 fl oz |
| 20 cup | 160 fl oz |
| 50 cup | 400 fl oz |
| 100 cup | 800 fl oz |
| 500 cup | 4000 fl oz |
| 1000 cup | 8000 fl oz |
How to convert US cups to fluid ounces
Multiply the us cup value by 8 to get the equivalent in fluid ounces. This single factor works for every value in the table above and for anything else you need — there is no per-value adjustment, which is why a conversion table and a calculator always agree.
If you need the opposite direction, use the Fluid ounces to US cups converter instead of dividing by hand; both pages use the same source factors. For every other cup conversion in one place, see the cup conversion hub.
Frequently asked questions
How many fluid ounces are in 1 us cup?
1 us cup = 8 fl oz.
What is 100 US cups in fluid ounces?
100 cup = 800 fl oz.
Is converting US cups to fluid ounces the same as fluid ounces to US cups?
No — the direction changes the multiplier. The reverse conversion (1 fl oz = 0.125 cup) is on the Fluid ounces to US cups page.
Related conversions
Try the ConvBolt Unit Converter for any other volume unit, browse the Volume conversions, or read our conversion guides.