# What is 4.5 quarts to cups?

Converts quarts (qt) to cups (cup) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/4-point-5-quarts-to-cups
- JSON spec: https://www.acalculator.org/convert/4-point-5-quarts-to-cups.json
- Version: 4c13b3b87d0b

## Default answer

Example with the default inputs (Quarts (qt) 4.5): 4.5 qt = 18 cups.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Quarts (qt) | The amount in quarts to convert. |
| result | Cups (cup) | The same amount in cups. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Quarts (qt) | The amount in quarts to convert. |
| result | Cups (cup) | The amount in cups. |

## Method

cup = qt × 4

## Assumptions

- 1 quart = 4 cups, from the exact definitions in NIST SP 811.
- Cups, ounces, tablespoons, teaspoons, pints, quarts, and gallons are US customary units: 1 US cup is 8 US fluid ounces.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up; an answer of 1 billion or more shows at most 15 significant digits.

## Worked examples

1. value = 1 gives result = 4. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 2.5 gives result = 10. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 10 gives value = 2.5. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### What is 4.5 quarts in cups?

4.5 qt is 18 cups. The formula is cup = qt × 4.

### How many cups are in a quart?

1 quart is 4 cups, from the exact unit definitions (NIST SP 811).

### How do I convert quarts to cups?

Multiply by 4: cup = qt × 4. For example, 4.5 qt × 4 = 18 cups.

### How do I convert cups back to quarts?

Multiply by 0.25, or type the cups into the second box and the converter works it out. 1 cup is 0.25 quarts.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B.8: Factors for Units Listed Alphabetically (bold factors are exact), retrieved 2026-10-18. https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8