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Convert tropical year to sidereal year

Here you can quickly calculate how many sidereal year fit in one tropical year.

- scroll: formula · table · questions -

  • 1 = 0.999961
  • 1 = 1.000039

Tropical year to sidereal year conversion table

tropical year sidereal year
1 0.999961
2 1.999922
5 4.999806
10 9.999612
20 19.999224
50 49.998061
100 99.996121

Tropical year to sidereal year formula

To convert tropical year to sidereal year, multiply by 0.999961.

1 = 0.999961
Example: 1 tropical year = 0.999961 sidereal year

Common time conversion mistakes

  • There are several year definitions: the Julian year is exactly 365.25 days, the Gregorian calendar year 365.2425, and the tropical year about 365.2422 days. For everyday use the differences are negligible, but they matter in astronomy, the light-year, for instance, is defined using the Julian year.

Quick tropical year and sidereal year conversion quiz

Score: 0

1 sidereal year equals 0.9 tropical year.

Correct answer: 1 sidereal year = 1 tropical year.

19.8 tropical year equals 19.8 sidereal year.

Correct answer: 19.8 tropical year = 19.8 sidereal year.

2.3 sidereal year equals 2.3 tropical year.

Correct answer: 2.3 sidereal year = 2.3 tropical year.

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