📏 au to μm — Astronomical Unit to Micrometer Converter

Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.

1 unit =
From
To
Formula 1 au = 1.4960e+17 μm
UnitNameValue
0.001 au1.496e+14 μm
0.01 au1.496e+15 μm
0.1 au1.496e+16 μm
1 au1.496e+17 μm
5 au7.480e+17 μm
10 au1.496e+18 μm
50 au7.480e+18 μm
100 au1.496e+19 μm
1000 au1.496e+20 μm

How to convert Astronomical Unit to Micrometer

Multiply the number of Astronomical Units by 1.496×1017 to get Micrometers. Formula: μm = au × 1.496×1017. Example: 10 au × 1.496×1017 = 1.496×1018 μm. To reverse, divide Micrometers by 1.496×1017 to get Astronomical Units.

Worked examples

Example 1
1 au × 1.496×1017 = 1.496×1017 μm
1 Astronomical Unit equals 1.496×1017 Micrometer.
Example 2
5 au × 1.496×1017 = 7.48×1017 μm
5 Astronomical Unit equals 7.48×1017 Micrometer.
Example 3
10 au × 1.496×1017 = 1.496×1018 μm
10 Astronomical Unit equals 1.496×1018 Micrometer.
Example 4 — reverse
1 μm = 6.6845×10-18 au
To convert back from Micrometer to Astronomical Unit, divide by 1.496×1017 or use the swap button above.

Astronomical Unit to Micrometer — reference table

Astronomical Unit (au)Micrometer (μm)
0.001 au1.496×1014 μm
0.01 au1.496×1015 μm
0.1 au1.496×1016 μm
0.5 au7.48×1016 μm
1 au1.496×1017 μm
2 au2.992×1017 μm
5 au7.48×1017 μm
10 au1.496×1018 μm
20 au2.992×1018 μm
50 au7.48×1018 μm
100 au1.496×1019 μm
250 au3.74×1019 μm
500 au7.48×1019 μm
1000 au1.496×1020 μm
10000 au1.496×1021 μm

Quick conversion tips

1
Multiply by 1.496×1017

To convert Astronomical Unit to Micrometer, multiply by 1.496×1017. Example: 10 au = 1.496×1018 μm

2
Reverse: divide by 1.496×1017

To convert Micrometer back to Astronomical Unit, divide by 1.496×1017 (multiply by 6.6845×10-18). Use the swap button above.

3
Round number check

Start with 100 Astronomical Units = 1.496×1019 μm as your reference point. Scale up or down from there.

Where astronomical unit to micrometer conversion is used

Infrared astronomy

Infrared telescopes like Spitzer and JWST observe at wavelengths of 1–300 micrometers. When modelling how dust emission from planetary systems (at AU distances) relates to these wavelengths, AU-to-μm conversion is routine.

Protoplanetary disk research

Astronomers studying protoplanetary disk structure describe disk radii in AU while analysing grain size distributions in micrometers — dust grain sizes directly influence how planetary systems form at AU-scale distances.

Space dust & meteorite science

Cosmic dust particles collected from space missions are measured in micrometers under electron microscopes, while their origin locations and collection trajectories are described in AU from the Sun.

Solar corona instrumentation

Coronagraph instruments blocking the Sun's light have occulter sizes measured in micrometers, while the Sun's corona extends to several AU — both scales appear in the same instrument design documentation.

Exozodiacal dust research

Researchers studying dust around other stars measure grain sizes in micrometers while describing their spatial distribution around the star in AU — conversion needed when modelling dust emission spectra.

Planetary surface science

Planetary geologists studying surface features at micrometer scale (grain size, rock texture) correlate findings with planet position in AU from the Sun to understand how solar irradiation drives geological processes.

Frequently asked questions

1 Astronomical Unit equals 1.496×1017 Micrometers. Multiply any Astronomical Unit value by 1.496×1017 to get Micrometers.
10 Astronomical Units equals 1.496×1018 Micrometers. (10 × 1.496×1017 = 1.496×1018)
100 Astronomical Units equals 1.496×1019 Micrometers. (100 × 1.496×1017 = 1.496×1019)
Divide Micrometer by 1.496×1017 to get Astronomical Units. Or multiply by 6.6845×10-18. Use the swap button on the converter above for instant reverse conversion.
Formula: μm = au × 1.496×1017. Example: 5 au × 1.496×1017 = 7.48×1017 μm.
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About Astronomical Unit and Micrometer

Astronomical Unit (au)

The Astronomical Unit is a unit of Length measurement (symbol: au). 1 au = 1.496×1017 μm. Used in scientific and practical Length measurement applications.

Micrometer (μm)

The Micrometer is a unit of Length measurement (symbol: μm). It is part of an internationally recognised measurement system used alongside the Astronomical Unit.

History & origin

The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC, estimating it at 18–20 lunar distances (the true value is about 390). For centuries the AU was estimated using Venus transit observations and trigonometry. Edmond Halley organised the first coordinated international transit-of-Venus expedition in 1716. The modern value was determined by radar ranging to Venus in 1961. The IAU formally defined the AU as exactly 149,597,870,700 metres in 2012 — a fixed constant of physics, not a measured distance.

The micrometre was named in 1879 by the International Committee for Weights and Measures. It became essential in the late 19th century as microscopy and precision engineering demanded a unit between the millimetre and nanometre. The micrometer screw gauge — a precision instrument now bearing the unit's common name — was first described by William Gascoigne in the 1630s, though the modern calliper was developed in the 1840s by Jean-Louis Palmer in France.

Common use: Astronomical Unit to Micrometer conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.