640 fl oz ≈ 66.6139 cup (Imperial; in US cups: 640 fl oz = 79.9999 US cup). To convert fluid ounces to cups, multiply by 0.10408423: 640 × 0.10408423 = 66.6139.
How to convert fluid ounces to cups
cup = fl oz × 0.10408423
- 1 fl oz = 0.10408423 cup (and 1 cup = 9.6076036 fl oz).
- Multiply the amount by the factor: 640 × 0.10408423 = 66.6139.
- Answer: 640 fl oz ≈ 66.6139 cup (rounded to 6 significant figures).
Fluid Ounces to Cups table
| Fluid Ounces (fl oz) | Cups (cup) |
|---|---|
| 635 fl oz | 66.0935 cup |
| 636 fl oz | 66.1976 cup |
| 637 fl oz | 66.3017 cup |
| 638 fl oz | 66.4057 cup |
| 639 fl oz | 66.5098 cup |
| 640 fl oz | 66.6139 cup |
| 641 fl oz | 66.718 cup |
| 642 fl oz | 66.8221 cup |
| 643 fl oz | 66.9262 cup |
| 644 fl oz | 67.0302 cup |
| 645 fl oz | 67.1343 cup |
| fl oz | cup |
|---|---|
| 1 fl oz | 0.104084 cup |
| 5 fl oz | 0.520421 cup |
| 10 fl oz | 1.0408 cup |
| 50 fl oz | 5.2042 cup |
| 100 fl oz | 10.4084 cup |
| 1,000 fl oz | 104.084 cup |
Good to know
The cup here is the Imperial (UK) cup: 1 cup = 0.28413 L. A US cup is 0.236588 L.
In US cups: 640 fl oz = 79.9999 US cup.
1 fl oz here is the US fluid ounce (29.5735 mL); a UK fluid ounce is 28.4131 mL.