# Cooking Measurement Converter

> Converts a kitchen volume between US customary units (teaspoon, tablespoon, fluid ounce, cup, pint, quart), the 250 ml metric cup, millilitres and litres using the exact US definitions.

- Calculator id: `cooking-converter` · Category: Food & Cooking (`food`) · Tool name: `convert_cooking_measurement`
- Canonical page: https://tttkmbb.com/food/cooking-converter · This document: https://tttkmbb.com/food/cooking-converter.md · JSON definition: https://tttkmbb.com/food/cooking-converter.json

## Purpose

Converts a kitchen volume between US customary units (teaspoon, tablespoon, fluid ounce, cup, pint, quart), the 250 ml metric cup, millilitres and litres using the exact US definitions.

**Use when:** A recipe uses cups, tablespoons or fluid ounces and you need millilitres (or the reverse), or you need to switch between US and metric cups.

**Do not use when:** You need grams: converting volume to weight requires the ingredient's density (e.g. 1 US cup of flour ≈ 120 g but of water ≈ 237 g), which this calculator does not do.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `value` | number |  | required | Quantity to convert, in from_unit. (min 0, max 1000000) |
| `from_unit` | enum: tsp \| tbsp \| fl_oz_us \| cup_us \| cup_metric \| ml \| l \| pint_us \| quart_us |  | required | Unit of the input amount. |
| `to_unit` | enum: tsp \| tbsp \| fl_oz_us \| cup_us \| cup_metric \| ml \| l \| pint_us \| quart_us |  | required | Unit to convert into. |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `result` | number |  | Amount expressed in to_unit. |
| `value_ml` | number | ml | Input amount converted to millilitres (intermediate step). |
| `conversion_factor` | number |  | Number of to_unit in one from_unit. |

## Formula

`result = value × ml_per(from_unit) / ml_per(to_unit); ml per unit: tsp 4.92892, tbsp 14.7868, fl oz 29.5735, US cup 236.588, metric cup 250, US pint 473.176, US quart 946.353, litre 1000`

US customary units follow their legal definitions (1 US gallon = 3.785411784 L exactly, 1 cup = 1/16 gallon). Nutrition labels and many recipe sites use the rounded 5 ml / 15 ml / 30 ml / 240 ml values, which differ by up to 1.5 %.

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the SI (Appendix B: US customary volume units in litres) — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-23)
- NIST – Metric Kitchen: cooking measurement equivalencies (rounded 5 / 15 / 30 / 240 ml values) — https://www.nist.gov/pml/owm/metric-si/metric-kitchen/metric-kitchen-cooking-measurement-equivalencies (government, retrieved 2026-09-23)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/cooking-converter?value=…&from_unit=…&to_unit=…`
- `POST https://tttkmbb.com/api/v1/calculate/cooking-converter` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/cooking-converter · OpenAPI operationId `convert_cooking_measurement` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "cooking-converter", "inputs": {…}}`

## Example

- 2 US cups to ml: inputs `{"value":2,"from_unit":"cup_us","to_unit":"ml"}` → `{"result":473.1765,"value_ml":473.176,"conversion_factor":236.588237}`
- 3 tablespoons to teaspoons: inputs `{"value":3,"from_unit":"tbsp","to_unit":"tsp"}` → `{"result":9,"conversion_factor":3}`

```
GET https://tttkmbb.com/api/v1/calculate/cooking-converter?value=2&from_unit=cup_us&to_unit=ml
```

## Limitations

You need grams: converting volume to weight requires the ingredient's density (e.g. 1 US cup of flour ≈ 120 g but of water ≈ 237 g), which this calculator does not do. US customary units follow their legal definitions (1 US gallon = 3.785411784 L exactly, 1 cup = 1/16 gallon). Nutrition labels and many recipe sites use the rounded 5 ml / 15 ml / 30 ml / 240 ml values, which differ by up to 1.5 %. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Is a UK or Australian cup the same?**

No. The metric cup (Australia, NZ, Canada) is 250 ml; the old imperial cup is 284 ml and the imperial fluid ounce 28.41 ml. Use cup_metric for 250 ml cups.

**How do I convert cups to grams?**

Multiply the millilitre amount by the ingredient's density in g/ml (water 1.0, sugar ≈ 0.85, all-purpose flour ≈ 0.51–0.55 depending on how it is scooped).

## Related

- [Recipe Scaler](https://tttkmbb.com/food/recipe-scaler.md) — Scale the recipe before or after converting units.
- [Cooking Measurement Converter](https://tttkmbb.com/conversion/cooking-measurements.md) — Full unit-conversion tool including weights.