HomeUnit Conversion › US cups to US fluid ounces

US cups to US fluid ounces (cup to fl oz)

Convert US cups to US fluid ounces: 1 cup = 8 fl oz. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

Formula

1 cup = 8 fl oz

US fluid ounces = US cups × 8 — reverse: US cups = US fluid ounces × 0.125

The factor is derived from the SI definitions of both units (base unit: L) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

US cups to US fluid ounces conversion table

US cups (cup)US fluid ounces (fl oz)
18
216
324
432
540
648
756
864
972
1080
15120
20160
25200
30240
40320
50400
75600
100800
2001600
2502000
5004000
10008000

FAQ

How many US fluid ounces are in one cup?

1 cup = 8 fl oz. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert US cups to US fluid ounces?

Multiply the value in US cups by 8: US fluid ounces = US cups × 8. For example, 5 cup = 40 fl oz.

How do I convert US fluid ounces back to US cups?

Multiply by the inverse factor 0.125 (US cups = US fluid ounces × 0.125), or use the US fluid ounces-to-US cups page.

Related conversions

Machine access

Sources