# How do I convert cups to teaspoons?

Converts cups (cup) to teaspoons (tsp) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/cups-to-teaspoons
- JSON spec: https://www.acalculator.org/convert/cups-to-teaspoons.json
- Version: 3479410ee518

## Default answer

Example with the default inputs (Cups (cup) 1): 1 cup = 48 tsp.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Cups (cup) | The amount in cups to convert. |
| result | Teaspoons (tsp) | The same amount in teaspoons. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Cups (cup) | The amount in cups to convert. |
| result | Teaspoons (tsp) | The amount in teaspoons. |

## Method

tsp = cup × 48

## Assumptions

- 1 cup = 48 teaspoons, 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.

## Worked examples

1. value = 1 gives result = 48. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 0.25 gives result = 12. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 12 gives value = 0.25. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### How many teaspoons are in a cup?

1 cup is 48 teaspoons, from the exact unit definitions (NIST SP 811).

### How do I convert cups to teaspoons?

Multiply by 48: tsp = cup × 48. For example, 1 cup × 48 = 48 tsp.

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

Multiply by 0.020833, or type the teaspoons into the second box and the converter works it out. 1 teaspoon is 0.020833 cups.

### How many teaspoons are in 1/4 cup?

12: 0.25 × 48. In 1/3 cup there are 16, and in 1/2 cup 24.

### How many teaspoons are in a tablespoon?

3. A US cup is 16 tablespoons, so it is 16 × 3 = 48 teaspoons.

### Are metric teaspoons different?

A little. A US teaspoon is 4.928922 mL, and a metric teaspoon is 5 mL (NIST). So a US cup is 48 US teaspoons, or about 47.3 metric teaspoons.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Table 5 (SI prefixes) and Appendix B.8 (factors for units listed alphabetically), retrieved 2026-10-05. https://www.nist.gov/pml/special-publication-811
- NIST Office of Weights and Measures, Metric Kitchen: Cooking Measurement Equivalencies (1 teaspoon = 5 mL, 1 tablespoon = 15 mL), retrieved 2026-10-05. https://www.nist.gov/pml/owm/metric-kitchen-cooking-measurement-equivalencies