# Miles per US gallon (mpg) to Kilometers per liter (mpg (US) to km/L)

> Convert miles per US gallon (mpg) to kilometers per liter with the formula km/L = mpg (US) × 0.425144. Conversion table and worked examples, with JSON API and MCP access.

- Page id: `mpg-to-km-per-liter` · Quantity: Fuel economy (`fuel-economy`, base unit L/100km) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/mpg-to-km-per-liter · This document: https://tttkmbb.com/conversion/mpg-to-km-per-liter.md · JSON: https://tttkmbb.com/conversion/mpg-to-km-per-liter.json (add `?value=` for a result)

## Formula

- `km/L = mpg (US) × 0.425144`
- `km/L = mpg (US) × 0.425144`
- Reverse: `mpg (US) = km/L × 2.352146`

Non-linear conversion: apply the formula directly; there is no single multiplication factor.

## Worked examples

- 7.5 mpg (US) = 3.18858 km/L
- 30 mpg (US) = 12.7543 km/L
- 45 mpg (US) = 19.1315 km/L

## Conversion table

| Miles per US gallon (mpg) (mpg (US)) | Kilometers per liter (km/L) |
| --- | --- |
| 3 | 1.27543 |
| 4 | 1.70057 |
| 5 | 2.12572 |
| 6 | 2.55086 |
| 7 | 2.97601 |
| 8 | 3.40115 |
| 9 | 3.82629 |
| 10 | 4.25144 |
| 12 | 5.10172 |
| 15 | 6.37716 |
| 20 | 8.50287 |
| 25 | 10.6286 |
| 30 | 12.7543 |
| 35 | 14.88 |
| 40 | 17.0057 |
| 45 | 19.1315 |
| 50 | 21.2572 |
| 60 | 25.5086 |
| 70 | 29.7601 |
| 80 | 34.0115 |
| 100 | 42.5144 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=7.5&from_unit=mpg_us&to_unit=km%2FL` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":7.5,"from_unit":"mpg_us","to_unit":"km/L"}`
- All fuel economy units: https://tttkmbb.com/api/v1/units?quantity=fuel-economy · full converter: [Fuel Economy Converter](https://tttkmbb.com/conversion/fuel-economy.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**What is the formula to convert miles per US gallon (mpg) to kilometers per liter?**

km/L = mpg (US) × 0.425144. For example, 7.5 mpg (US) = 3.18858 km/L.

**How do I convert kilometers per liter back to miles per US gallon (mpg)?**

mpg (US) = km/L × 2.352146; the kilometers per liter-to-miles per US gallon (mpg) page applies it directly.

**Why is there no single multiplication factor?**

Fuel-economy units are reciprocal (distance per volume versus volume per distance), so the conversion divides a constant by the value instead of multiplying.

## Related conversions

- [Kilometers per liter to miles per US gallon (mpg)](https://tttkmbb.com/conversion/km-per-liter-to-mpg.md) (reverse)
- [Miles per US gallon (mpg) to Liters per 100 km](https://tttkmbb.com/conversion/mpg-to-l-per-100km.md)
- [Liters per 100 km to Miles per US gallon (mpg)](https://tttkmbb.com/conversion/l-per-100km-to-mpg.md)
- [Miles per imperial gallon (UK mpg) to Liters per 100 km](https://tttkmbb.com/conversion/mpg-uk-to-l-per-100km.md)
- [Liters per 100 km to Miles per imperial gallon (UK mpg)](https://tttkmbb.com/conversion/l-per-100km-to-mpg-uk.md)
- [Kilometers per liter to Liters per 100 km](https://tttkmbb.com/conversion/km-per-liter-to-l-per-100km.md)
- [Liters per 100 km to Kilometers per liter](https://tttkmbb.com/conversion/l-per-100km-to-km-per-liter.md)
- [Miles per US gallon (mpg) to Miles per imperial gallon (UK mpg)](https://tttkmbb.com/conversion/mpg-to-mpg-uk.md)
- [Miles per imperial gallon (UK mpg) to Miles per US gallon (mpg)](https://tttkmbb.com/conversion/mpg-uk-to-mpg.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)