A US liquid quart contains 4 US customary cups. Use cups to quarts for a cup total, or quarts to cups for a quart source and an optional reverse direction.
Inputs and supporting results
| Cups to quarts | Quarts to cups | |
|---|---|---|
| Controls | Nonnegative cups | Direction selector and the active quarts or cups field |
| Default | 8 cups | 2 quarts, quarts-to-cups mode |
| Primary result | 2 qt | 8 cups |
| Calculation | cups ÷ 4 | quarts × 4; reverse cups ÷ 4 |
| Details | Pints and gallons | Entered amount, factor and reverse check |
| Primary rounding | Up to 4 decimal places | Up to 4 decimal places |
The cups-first form also divides by 2 for pints and by 16 for gallons. Its default 8 cups is 2 qt, 4 pt and 0.5 gal. The other form has a real reverse mode, not just a reverse-result detail: choose cups-to-quarts to enter cups directly.
Worked conversions
18 cups ÷ 4 = 4.5 qt. This volume is larger than 4 qt; converting it does not determine a vessel’s usable capacity. In the other direction, 2.75 qt × 4 = 11 cups.
Unit and rounding limits
These are US liquid measures with an 8-US-fluid-ounce customary cup. Do not substitute an imperial quart or a differently defined cup. The factor is exact for this stated system; rounded readouts and original measurement uncertainty remain separate. Neither form calculates cooking headspace, canning suitability or serving safety.
Sources
NIST SP 811, unit definitions and Appendix B factors. The paired calculator controls and rounding described above are their current form behavior. NIST Handbook 44, Appendix C, customary unit relationships.