Parallax Distance Calculator Formula
Understand the math behind the parallax distance calculator. Each variable explained with a worked example.
Formulas Used
Distance (parsecs)
distance_pc = 1 / parallax_arcsecDistance (light-years)
distance_ly = 3.26156 / parallax_arcsecVariables
| Variable | Description | Default |
|---|---|---|
parallax_arcsec | Parallax Angle(arcsec) | 0.772 |
How It Works
Stellar Parallax
As Earth orbits the Sun, nearby stars shift against the background. The parallax angle p relates to distance:
d (parsecs) = 1 / p (arcseconds)
A star with 1 arcsecond parallax is exactly 1 parsec away.
Worked Example
Alpha Centauri has a parallax of 0.772 arcseconds.
parallax_arcsec = 0.772
- 01d = 1 / 0.772 = 1.295 pc
- 02In ly: 1.295 × 3.262 = 4.225 ly
Ready to run the numbers?
Open Parallax Distance Calculator