Parallax Star Distance Calculator
Fill in the value and the answer updates as you type.
How the Parallax Star Distance Calculator works
Parallax is the tiny shift in a star position as Earth moves around the Sun. Distance in parsecs = 1 ÷ parallax in arcseconds, or 1,000 ÷ parallax in milliarcseconds (mas). A parsec is 3.26156 light-years or 206,265 astronomical units. Parallax is reliable only for stars within a few thousand parsecs, where the angle is still measurable. Example: with Parallax angle 100 mas, the result is Distance (parsecs) = 10; Distance (light-years) = 32.62; Distance (astronomical units) = 2,062,648.
Inputs and results
The Parallax Star Distance Calculator takes 1 input and gives 3 results.
What you enter
- Parallax angle (mas) — starts at 100.
What you get
- Distance (parsecs)
- Distance (light-years)
- Distance (astronomical units)
Example: Parallax Star Distance Calculator with the starting values
With parallax angle 100 mas, the calculator returns:
| Distance (parsecs) | 10 |
|---|---|
| Distance (light-years) | 32.62 |
| Distance (astronomical units) | 2,062,648 |
Change any value above and the results update straight away.
Parallax Star Distance Calculator FAQ
How do I use the Parallax Star Distance Calculator?
Enter parallax angle in the fields, then read distance (parsecs), distance (light-years) and distance (astronomical units) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Parallax Star Distance Calculator calculate?
Distance to a nearby star from its measured parallax angle. It returns distance (parsecs), distance (light-years) and distance (astronomical units) from the 1 value you provide.
What values does the Parallax Star Distance Calculator start with?
It opens with parallax angle 100 mas so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Parallax Star Distance Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Parallax Star Distance Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.