Parallax Distance Calculator

Hamza Gujjar Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer Last updated: July 27, 2026

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The most direct way to measure a star's distance

Parallax measures the tiny apparent shift in a star's position against distant background stars as Earth orbits the Sun, observed from opposite points 6 months apart - the most fundamental and reliable geometric method for measuring stellar distances.

Worked example

For a parallax angle of 0.379 arcseconds (Sirius's actual measured parallax):

Distance = 1 / 0.379 = 2.6385 parsecs (8.606 light-years)

This result matches Sirius's real, well-documented distance of about 8.6 light-years almost exactly - and it's exactly where the distance unit "parsec" gets its name: a "parallax of one arcsecond" corresponds to a distance of one parsec by definition.