---
title: "Astronomical units to Millimeters — AU to mm converter"
description: "1 astronomical unit = 149,597,870,000,000 millimeters. Conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/astronomical-units-to-mm/
site: "At One Place"
---

# Astronomical units to millimeters

**1 astronomical unit in millimeters: 1 AU = 149,597,870,000,000 mm**

mm = AU × 149,597,870,700,000

To convert astronomical units to millimeters, multiply by 149,597,870,700,000. The table below gives the values people look up most often, and the converter works for any number.

## Astronomical units to millimeters table

*Common astronomical unit values converted to millimeters.*

| Astronomical units | Millimeters |
| --- | --- |
| 1 AU | 149,597,870,000,000 |
| 2 AU | 299,195,740,000,000 |
| 3 AU | 448,793,610,000,000 |
| 4 AU | 598,391,480,000,000 |
| 5 AU | 747,989,350,000,000 |
| 10 AU | 1.4959787 × 10^15 |
| 15 AU | 2.2439681 × 10^15 |
| 20 AU | 2.9919574 × 10^15 |
| 25 AU | 3.7399468 × 10^15 |
| 30 AU | 4.4879361 × 10^15 |
| 40 AU | 5.9839148 × 10^15 |
| 50 AU | 7.4798935 × 10^15 |
| 75 AU | 1.121984 × 10^16 |
| 100 AU | 1.4959787 × 10^16 |
| 250 AU | 3.7399468 × 10^16 |
| 500 AU | 7.4798935 × 10^16 |
| 1,000 AU | 1.4959787 × 10^17 |

## How the conversion works

The relationship is mm = AU × 149,597,870,700,000. Both units measure length, so the conversion is a fixed factor that never changes.

## Common questions

### How many millimeters are in one astronomical unit?

One astronomical unit equals 149,597,870,000,000 millimeters. mm = AU × 149,597,870,700,000.

### How do you convert astronomical units to millimeters?

Use mm = AU × 149,597,870,700,000. So 10 AU is 1.4959787 × 10^15 mm.

### How many astronomical units are in one millimeter?

One millimeter equals 6.685 × 10^-15 astronomical units, which is the reverse of the conversion above.

## Related pages

- [Millimeters to Astronomical units](https://atoneplace.net/convert/mm-to-astronomical-units/)
- [Astronomical units to Meters](https://atoneplace.net/convert/astronomical-units-to-meters/)
- [Astronomical units to Kilometers](https://atoneplace.net/convert/astronomical-units-to-km/)
- [Astronomical units to Centimeters](https://atoneplace.net/convert/astronomical-units-to-cm/)
- [Astronomical units to Miles](https://atoneplace.net/convert/astronomical-units-to-miles/)
- [Astronomical units to Yards](https://atoneplace.net/convert/astronomical-units-to-yards/)
- [Astronomical units to Feet](https://atoneplace.net/convert/astronomical-units-to-feet/)
- [Astronomical units to Inches](https://atoneplace.net/convert/astronomical-units-to-inches/)

## 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/)