# Volume Converter

> Converts volumes between metric units (mL, L, cm³, m³), US customary units (tsp to gallon, in³, ft³, yd³, oil barrel), imperial units (fl oz, pint, quart, gallon) and metric kitchen units, with exact definitions (1 US gal = 3.785411784 L, 1 imperial gal = 4.54609 L).

- Calculator id: `volume` · Category: Unit Conversion (`conversion`) · Tool name: `convert_volume`
- Canonical page: https://tttkmbb.com/conversion/volume · This document: https://tttkmbb.com/conversion/volume.md · JSON definition: https://tttkmbb.com/conversion/volume.json

## Purpose

Converts volumes between metric units (mL, L, cm³, m³), US customary units (tsp to gallon, in³, ft³, yd³, oil barrel), imperial units (fl oz, pint, quart, gallon) and metric kitchen units, with exact definitions (1 US gal = 3.785411784 L, 1 imperial gal = 4.54609 L).

**Use when:** You need a liquid or bulk volume in another unit, e.g. gallons to litres, cubic feet to cubic metres or millilitres to cups.

**Do not use when:** You need a volume from dimensions (use cylinder, sphere or rectangular-prism), a recipe conversion with tablespoons and cups only (cooking-measurements is a focused subset), or mass from volume (use density).

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `value` | number |  | required | Amount to convert, expressed in from_unit. |
| `from_unit` | enum: mL \| L \| m3 \| cm3 \| tsp \| tbsp \| fl_oz_us \| cup_us \| pint_us \| quart_us \| gal_us \| fl_oz_uk \| pint_uk \| quart_uk \| gal_uk \| in3 \| ft3 \| yd3 \| bbl \| tsp_metric \| tbsp_metric \| cup_metric |  | required | Unit of the input value. Accepted symbols: mL, L, m3, cm3, tsp, tbsp, fl_oz_us, cup_us, pint_us, quart_us, gal_us, fl_oz_uk, pint_uk, quart_uk, gal_uk, in3, ft3, yd3, bbl, tsp_metric, tbsp_metric, cup_metric; spelled-out names and common abbreviations are accepted too. |
| `to_unit` | enum: mL \| L \| m3 \| cm3 \| tsp \| tbsp \| fl_oz_us \| cup_us \| pint_us \| quart_us \| gal_us \| fl_oz_uk \| pint_uk \| quart_uk \| gal_uk \| in3 \| ft3 \| yd3 \| bbl \| tsp_metric \| tbsp_metric \| cup_metric |  | required | Unit to convert into (same symbols as from_unit). |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `result` | number |  | Converted value expressed in to_unit (rounded to 6 decimals; see result_text for very small or very large values). |
| `result_text` | string |  | The conversion as text with 6 significant figures, e.g. "5 mi = 8.04672 km". |
| `formula` | string |  | Relation used, e.g. "1 mi = 1.609344 km". |
| `factor` | number |  | Multiplier from from_unit to to_unit (result = value × factor); absent for non-linear conversions. |
| `conversion_table` | object |  | The input value expressed in every supported volume unit (6 significant figures), keyed by unit symbol. |

## Formula

`result = value × factor, factor = (1 from_unit in L) / (1 to_unit in L)`

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-23)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-23)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, 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/volume?value=…&from_unit=…&to_unit=…`
- `POST https://tttkmbb.com/api/v1/calculate/volume` 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/volume · OpenAPI operationId `convert_volume` 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": "volume", "inputs": {…}}`

## Example

- 1 US gallon to litres: inputs `{"value":1,"from_unit":"gal_us","to_unit":"L"}` → `{"result":3.785412,"factor":3.785411784,"formula":"1 gal_us = 3.785411784 L","conversion_table":{"mL":3785.41,"fl_oz_us":128,"gal_uk":0.832674}}`
- 500 mL to US cups: inputs `{"value":500,"from_unit":"mL","to_unit":"cup_us"}` → `{"result":2.113376,"conversion_table":{"fl_oz_us":16.907,"L":0.5}}`

```
GET https://tttkmbb.com/api/v1/calculate/volume?value=1&from_unit=gal_us&to_unit=L
```

## Limitations

You need a volume from dimensions (use cylinder, sphere or rectangular-prism), a recipe conversion with tablespoons and cups only (cooking-measurements is a focused subset), or mass from volume (use density). All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**US or imperial gallon?**

The plain aliases gal, gallon, pint, quart, fl oz and cup resolve to US customary units; imperial units are gal_uk, pint_uk, quart_uk and fl_oz_uk (an imperial gallon is about 20% larger).

**Is a millilitre the same as a cubic centimetre?**

Yes, exactly: 1 mL = 1 cm³ = 1 cc, and 1 L = 1 dm³ = 0.001 m³.

**Which barrel is bbl?**

The US oil barrel of 42 US gallons (158.987294928 L). Beer and other barrels differ.

## Related

- [Cooking Measurement Converter](https://tttkmbb.com/conversion/cooking-measurements.md) — Kitchen-only subset with teaspoons, tablespoons and cups.
- [Cylinder Calculator](https://tttkmbb.com/geometry/cylinder.md) — Compute tank volume from dimensions.
- [Density Converter](https://tttkmbb.com/conversion/density.md) — Convert volume to mass with a density.