# Micrometers to Astronomical Units (μm to au)

Source: https://www.unitconvertercalculator.com/length/micrometers-to-astronomical-units/

**1 μm = 6.6845871222684E-18 au**

One micrometer equals approximately 6.685 x 10-18 astronomical units. The AU (149.6 billion meters) measures planetary distances; the micrometer measures cells and precision tolerances. About 17 orders of magnitude separate them.

## Formula

Convert Micrometers to Astronomical Units

## Conversion Table

| Micrometers (μm) | Astronomical Units (au) |
|---|---|
| 1 μm | 6.68E-18 au |
| 100 μm | 6.6845E-16 au |
| 10000 μm | 6.684587E-14 au |
| 1000000 μm | 6.68458712E-12 au |
| 100000000 μm | 6.6845871222E-10 au |
| 10000000000 μm | 6.684587122268E-8 au |
| 1000000000000 μm | 6.6845871222684E-6 au |
| 100000000000000 μm | 0.00066845871222684 au |
| 10000000000000000 μm | 0.066845871222684 au |

## Units

### Micrometer (μm)

One millionth of a meter, also called a micron. Used in biology for cell sizes, in engineering for surface finishes, and in manufacturing tolerances.

### Astronomical Unit (au)

Exactly 149,597,870,700 meters by IAU 2012 definition. Roughly the average distance from the Earth to the Sun. Used for distances within our solar system.

## Background

The Earth-Sun distance is about 1.496 x 1017 micrometers. A red blood cell at 7 um is 4.68 x 10-17 AU across. These units occupy completely separate measurement domains.

## Good to Know

The micrometer measures the machinery of life. The AU measures the arrangement of planets. Both units describe systems that operate mechanically: cells divide on schedules, planets orbit on schedules. The scales differ by 1017 but the principle of regular motion is the same.

## FAQ

### How many AU is 1 micrometer?

One micrometer equals approximately 6.685 x 10-18 AU.

### How many micrometers are in 1 AU?

One AU contains approximately 1.496 x 1017 um (about 150 quadrillion).

### Is this conversion practical?

No. Cells and planetary orbits exist at scales separated by 17 orders of magnitude with no practical overlap.

## Non-Frequently Asked Questions

### How many bacteria fit between Earth and the Sun?

A bacterium is about 2 um. The Earth-Sun distance is 1.496 x 1017 um. That is about 75 quadrillion bacteria in a line. Earth has about 1030 bacteria total - enough to span this distance about 13 million times over. There are far more bacteria than space to put them.

### How many red blood cells span 1 AU?

A red blood cell is 7 um. 1 AU = 1.496 x 1017 um. That is about 21.4 quadrillion cells. Your body has about 25 trillion red blood cells - enough to span only 0.12% of the Earth-Sun distance. You are small.

### If a dust mite traveled 1 micrometer per second, how long to reach the Sun?

1.496 x 1017 seconds = about 4.74 billion years. The Sun has about 5 billion years of fuel left. The dust mite would arrive just as the Sun starts to die. Terrible timing.

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## See Also

- [Astronomical Units to Micrometers](https://www.unitconvertercalculator.com/length/astronomical-units-to-micrometers/)