📏 in to au — Inch to Astronomical Unit Converter

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

1 unit =
From
To
Formula 1 in = 1.6979e-13 au
UnitNameValue
0.001 in1.698e-16 au
0.01 in1.698e-15 au
0.1 in1.698e-14 au
1 in1.698e-13 au
5 in8.489e-13 au
10 in1.698e-12 au
50 in8.489e-12 au
100 in1.698e-11 au
1000 in1.698e-10 au

How to convert Inch to Astronomical Unit

Multiply the number of Inchs by 1.6979×10-13 to get Astronomical Units. Formula: au = in × 1.6979×10-13. Example: 10 in × 1.6979×10-13 = 1.6979×10-12 au. To reverse, divide Astronomical Units by 1.6979×10-13 to get Inchs.

Worked examples

Example 1
1 in × 1.6979×10-13 = 1.6979×10-13 au
1 Inch equals 1.6979×10-13 Astronomical Unit.
Example 2
5 in × 1.6979×10-13 = 8.4893×10-13 au
5 Inch equals 8.4893×10-13 Astronomical Unit.
Example 3
10 in × 1.6979×10-13 = 1.6979×10-12 au
10 Inch equals 1.6979×10-12 Astronomical Unit.
Example 4 — reverse
1 au = 5.8898×1012 in
To convert back from Astronomical Unit to Inch, divide by 1.6979×10-13 or use the swap button above.

Inch to Astronomical Unit — reference table

Inch (in)Astronomical Unit (au)
0.001 in1.6979×10-16 au
0.01 in1.6979×10-15 au
0.1 in1.6979×10-14 au
0.5 in8.4893×10-14 au
1 in1.6979×10-13 au
2 in3.3957×10-13 au
5 in8.4893×10-13 au
10 in1.6979×10-12 au
20 in3.3957×10-12 au
50 in8.4893×10-12 au
100 in1.6979×10-11 au
250 in4.2447×10-11 au
500 in8.4893×10-11 au
1000 in1.6979×10-10 au
10000 in1.6979×10-9 au

Quick conversion tips

1
Multiply by 1.6979×10-13

To convert Inch to Astronomical Unit, multiply by 1.6979×10-13. Example: 10 in = 1.6979×10-12 au

2
Reverse: divide by 1.6979×10-13

To convert Astronomical Unit back to Inch, divide by 1.6979×10-13 (multiply by 5.8898×1012). Use the swap button above.

3
Round number check

Start with 100 Inchs = 1.6979×10-11 au as your reference point. Scale up or down from there.

Where inch to astronomical unit conversion is used

Solar system scale models

The classic classroom solar system model at 1 AU = 1 inch scale puts Mercury at 0.39 inches from the "Sun" and Neptune at 30 inches — fitting on a desk. US science teachers build these to make planetary distances intuitive.

NASA engineering documents

US aerospace engineers specify hardware dimensions in inches while orbital distances use AU. Both units appear in the same mission document — component dimensions in inches, trajectory distances in AU.

Extreme scale illustration

1 AU = 5.89×10¹² inches — nearly 6 trillion inches. Science communicators use this to make the Earth-Sun distance tangible for US audiences: "5.9 trillion inch-rulers laid end to end reaches the Sun."

US physics education

American university physics courses use inch-to-AU conversion in dimensional analysis exercises — requiring students to bridge US customary units with astronomical standards used in planetary science.

Amateur astronomy outreach

US amateur astronomers who think in inches and feet convert AU distances to inches for scale comparison: "Jupiter is 5.2 AU from the Sun — that's 30.6 trillion inches, or 483 million miles."

Space telescope optics

Hubble's primary mirror is 94.5 inches (2.4 m) in diameter while targets are measured in AU and parsecs. Engineers and astronomers bridge both scales in every telescope performance specification.

Frequently asked questions

1 Inch equals 1.6979×10-13 Astronomical Units. Multiply any Inch value by 1.6979×10-13 to get Astronomical Units.
10 Inchs equals 1.6979×10-12 Astronomical Units. (10 × 1.6979×10-13 = 1.6979×10-12)
100 Inchs equals 1.6979×10-11 Astronomical Units. (100 × 1.6979×10-13 = 1.6979×10-11)
Divide Astronomical Unit by 1.6979×10-13 to get Inchs. Or multiply by 5.8898×1012. Use the swap button on the converter above for instant reverse conversion.
Formula: au = in × 1.6979×10-13. Example: 5 in × 1.6979×10-13 = 8.4893×10-13 au.
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About Inch and Astronomical Unit

Inch (in)

The Inch is a unit of Length measurement (symbol: in). 1 in = 1.6979×10-13 au. Used in scientific and practical Length measurement applications.

Astronomical Unit (au)

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

History & origin

The inch has one of the most colourful origin stories in measurement history. An English statute from 1324 under King Edward II defined it as 'three grains of barley, dry and round, placed end to end'. Before that, it was often defined as the width of a thumb — hence the word in many languages (French: 'pouce', Dutch: 'duim', both meaning thumb). The inch was standardised at exactly 25.4 mm in 1959 under the International Yard and Pound Agreement signed by the US, UK, Canada, Australia, and South Africa. It remains dominant in the US and is universally used for screen sizes globally.

The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC. For centuries the AU was estimated using Venus transit observations. 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.

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