# Milliliters to US fluid ounces (mL to fl oz)

> Convert milliliters to US fluid ounces: 1 mL = 0.033814 fl oz. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `ml-to-fl-oz` · Quantity: Volume (`volume`, base unit L) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/ml-to-fl-oz · This document: https://tttkmbb.com/conversion/ml-to-fl-oz.md · JSON: https://tttkmbb.com/conversion/ml-to-fl-oz.json (add `?value=` for a result)

## Formula

- `1 mL = 0.033814 fl oz`
- `US fluid ounces = milliliters × 0.0338140227`
- Reverse: `milliliters = US fluid ounces × 29.57352956`

The factor follows from the SI definitions of both units (NIST SP 811); values below are rounded to 6 significant figures, the API returns up to 12.

## Worked examples

- 5 mL = 0.16907 fl oz
- 12.5 mL = 0.422675 fl oz
- 100 mL = 3.3814 fl oz

## Conversion table

| Milliliters (mL) | US fluid ounces (fl oz) |
| --- | --- |
| 1 | 0.033814 |
| 2 | 0.067628 |
| 3 | 0.101442 |
| 4 | 0.135256 |
| 5 | 0.16907 |
| 6 | 0.202884 |
| 7 | 0.236698 |
| 8 | 0.270512 |
| 9 | 0.304326 |
| 10 | 0.33814 |
| 15 | 0.50721 |
| 20 | 0.67628 |
| 25 | 0.845351 |
| 30 | 1.01442 |
| 40 | 1.35256 |
| 50 | 1.6907 |
| 75 | 2.53605 |
| 100 | 3.3814 |
| 200 | 6.7628 |
| 250 | 8.45351 |
| 500 | 16.907 |
| 1000 | 33.814 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=mL&to_unit=fl_oz_us` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":5,"from_unit":"mL","to_unit":"fl_oz_us"}`
- All volume units: https://tttkmbb.com/api/v1/units?quantity=volume · full converter: [Volume Converter](https://tttkmbb.com/conversion/volume.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many US fluid ounces are in one milliliter?**

1 mL = 0.033814 fl oz. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

**What is the formula to convert milliliters to US fluid ounces?**

Multiply the value in milliliters by 0.0338140227: US fluid ounces = milliliters × 0.0338140227. For example, 5 mL = 0.16907 fl oz.

**How do I convert US fluid ounces back to milliliters?**

Multiply by the inverse factor 29.57352956 (milliliters = US fluid ounces × 29.57352956), or use the US fluid ounces-to-milliliters page.

## Related conversions

- [US fluid ounces to milliliters](https://tttkmbb.com/conversion/fl-oz-to-ml.md) (reverse)
- [Liters to US gallons](https://tttkmbb.com/conversion/liters-to-gallons.md)
- [US gallons to Liters](https://tttkmbb.com/conversion/gallons-to-liters.md)
- [Liters to Milliliters](https://tttkmbb.com/conversion/liters-to-ml.md)
- [Milliliters to Liters](https://tttkmbb.com/conversion/ml-to-liters.md)
- [US cups to Milliliters](https://tttkmbb.com/conversion/cups-to-ml.md)
- [Milliliters to US cups](https://tttkmbb.com/conversion/ml-to-cups.md)
- [US tablespoons to Milliliters](https://tttkmbb.com/conversion/tablespoons-to-ml.md)
- [Milliliters to US tablespoons](https://tttkmbb.com/conversion/ml-to-tablespoons.md)

## 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 2026-09-24)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-24)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, retrieved 2026-09-24)