---
title: "Miles per hour to Times the speed of light converter"
description: "1 mile per hour = 1.491 × 10^-9 times the speed of light. Conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/mph-to-speed-of-light/
site: "At One Place"
---

# Miles per hour to times the speed of light

**1 mile per hour in times the speed of light: 1 mph = 1.491 × 10^-9 c**

c = mph × 1.491164931 × 10^-9

To convert miles per hour to times the speed of light, multiply by 1.491164931 × 10^-9. The table below gives the values people look up most often, and the converter works for any number.

## Miles per hour to times the speed of light table

*Common mile per hour values converted to times the speed of light.*

| Miles per hour | Times the speed of light |
| --- | --- |
| 1 mph | 1.491 × 10^-9 |
| 2 mph | 2.982 × 10^-9 |
| 3 mph | 4.473 × 10^-9 |
| 4 mph | 5.965 × 10^-9 |
| 5 mph | 7.456 × 10^-9 |
| 10 mph | 1.491 × 10^-8 |
| 15 mph | 2.237 × 10^-8 |
| 20 mph | 2.982 × 10^-8 |
| 25 mph | 3.728 × 10^-8 |
| 30 mph | 4.473 × 10^-8 |
| 40 mph | 5.965 × 10^-8 |
| 50 mph | 7.456 × 10^-8 |
| 75 mph | 1.118 × 10^-7 |
| 100 mph | 1.491 × 10^-7 |
| 250 mph | 3.728 × 10^-7 |
| 500 mph | 7.456 × 10^-7 |
| 1,000 mph | 0.000001491 |

## How the conversion works

The relationship is c = mph × 1.491164931 × 10^-9. Both units measure speed, so the conversion is a fixed factor that never changes.

> Speed of light: Exact by definition.

## Common questions

### How many times the speed of light are in one mile per hour?

One mile per hour equals 1.491 × 10^-9 times the speed of light. c = mph × 1.491164931 × 10^-9.

### How do you convert miles per hour to times the speed of light?

Use c = mph × 1.491164931 × 10^-9. So 10 mph is 1.491 × 10^-8 c.

### How many miles per hour are in one speed of light?

One speed of light equals 670,616,630 miles per hour, which is the reverse of the conversion above.

### Is there more than one kind of speed of light?

Exact by definition.

## Related pages

- [Times the speed of light to Miles per hour](https://atoneplace.net/convert/speed-of-light-to-mph/)
- [Miles per hour to Meters per second](https://atoneplace.net/convert/mph-to-meters-per-second/)
- [Miles per hour to Kilometers per hour](https://atoneplace.net/convert/mph-to-kmh/)
- [Miles per hour to Knots](https://atoneplace.net/convert/mph-to-knots/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)