This page converts nanometers into astronomical units using the factor 6.684587122e-21, and shows the reverse figure alongside it. Both units measure length, which is why one number does the whole job.
Exactly 149,597,870,700 metres — the Earth–Sun distance, and the natural ruler for the solar system. One billionth of a metre — the scale of light wavelengths and chip lithography.
The mil and the millimetre are not the same thing and are out by a factor of about forty. A mil is one thousandth of an inch — 0.0254 mm — and a spec sheet that quotes film thickness in mils means the small unit. British drawings write the same size as "thou". The tables underneath give both a plain step-by-step lookup and a list of real quantities expressed in astronomical units, so you can sanity-check whether your answer is a plausible size.
The formula
nanometers- The amount you are converting, in nanometers
6.68458712227e-21- The exact number of astronomical units in one nanometer
astronomical units- The converted result
How it works, step by step
- Enter the value in nanometers.
- It is multiplied by 6.68458712227e-21, the exact factor between the two units.
- The answer is shown in astronomical units, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A larger figure: 100 nm in astronomical units
Take a larger figure, roughly 100 nm. The conversion is a single multiplication — 100 × 6.68459e-21 — giving 6.68459e-19 AU. Because the relationship is proportional, doubling the input doubles the answer to 1.33692e-18 AU.
A round figure: 1 nm in astronomical units
At 1 nm (a round figure), the same quantity in astronomical units is 1 × 6.68459e-21 = 6.68459e-21 AU. One nanometer is 6.68459e-21 astronomical units, so the numbers shrink as expected.
How to read your score
Frequently asked questions
How many astronomical units are in one nanometer?
Exactly 6.68458712227e-21. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert nanometers to astronomical units?
astronomical units = nanometers × 6.68458712227e-21. Reversed, nanometers = astronomical units ÷ 6.68458712227e-21, which is the same as multiplying by 1.49597870700e+20.
Which is the bigger unit, the nanometer or the astronomical unit?
The astronomical unit. One nanometer is only 6.68459e-21 of a astronomical unit, so it takes 1.49598e+20 nanometers to make one astronomical unit.
What does this quantity actually measure?
Both units measure length. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a nanometer?
One billionth of a metre — the scale of light wavelengths and chip lithography.
What is a astronomical unit?
Exactly 149,597,870,700 metres — the Earth–Sun distance, and the natural ruler for the solar system.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Nanometers to astronomical units reference tables
| Nanometers | Astronomical Units |
|---|---|
| 0.5 nm | 3.34229e-21 AU |
| 1 nm | 6.68459e-21 AU |
| 2 nm | 1.33692e-20 AU |
| 3 nm | 2.00538e-20 AU |
| 5 nm | 3.34229e-20 AU |
| 10 nm | 6.68459e-20 AU |
| 20 nm | 1.33692e-19 AU |
| 25 nm | 1.67115e-19 AU |
| 50 nm | 3.34229e-19 AU |
| 75 nm | 5.01344e-19 AU |
| 100 nm | 6.68459e-19 AU |
| 250 nm | 1.67115e-18 AU |
| 500 nm | 3.34229e-18 AU |
| 1000 nm | 6.68459e-18 AU |
| 5000 nm | 3.34229e-17 AU |
Exact factor: 1 nanometer = 6.68458712227e-21 astronomical units.
| Quantity | nm | AU |
|---|---|---|
| A credit card’s long edge | 8.56e+07 nm | 5.722e-13 AU |
| A door height | 2.032e+09 nm | 1.358e-11 AU |
| An Olympic pool | 5e+10 nm | 3.342e-10 AU |
| The Eiffel Tower | 3.3e+11 nm | 2.206e-09 AU |
| A marathon | 4.22e+13 nm | 2.821e-07 AU |
| Earth’s diameter | 1.274e+16 nm | 8.518e-05 AU |
Published reference values, converted with the same factor this page uses.