Year (365 days) to Sidereal Day Converter

Time Converter

21 units available

Decimals:

From

To

365.999337

1 yr = 365.999337 sid day

Formula:

sid day = yr × 365.999337044

With your value: 1 yr = 365.99933704 sid day

How big is that?

Everyday references on a logarithmic scale, all expressed in year (365 days) so you can sanity-check the result.

Minute (1/5.3e+5 your value)0.00000190 yr

Working day (1/1.1e+3 your value)0.000913 yr

Day (1/3.7e+2 your value)0.00274 yr

Week (1/52 your value)0.0192 yr

Your value1.00 yr

Year (1.0× your value)1.00 yr

Other Year (365 days) to Sidereal Day conversions

2 yr to sid day 3 yr to sid day 4 yr to sid day 5 yr to sid day 6 yr to sid day 7 yr to sid day 8 yr to sid day

Year (365 days) to Sidereal Day Conversion Table

Year (365 days) (yr)	Sidereal Day (sid day)
0.5	182.999669
1	365.999337
2	731.998674
5	1,829.996685
10	3,659.99337
15	5,489.990056
20	7,319.986741
25	9,149.983426
50	18,299.966852
100	36,599.933704
250	91,499.834261
500	182,999.668522
1000	365,999.337044

Sidereal Day to Year (365 days) Conversion Table

Sidereal Day (sid day)	Year (365 days) (yr)
0.5	0.001366
1	0.002732
2	0.005464
5	0.013661
10	0.027322
15	0.040984
20	0.054645
25	0.068306
50	0.136612
100	0.273225
250	0.683061
500	1.366123
1000	2.732245

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Year (365 days) (yr)

Time

SI definition

Traceable to the second, defined by fixing the caesium-133 hyperfine transition frequency at 9 192 631 770 Hz.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Sidereal Day (sid day)

Time

SI definition

Traceable to the second, defined by fixing the caesium-133 hyperfine transition frequency at 9 192 631 770 Hz.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Year (365 days) to Sidereal Day

To convert from Year (365 days) (yr) to Sidereal Day (sid day), multiply the value by 365.999337044.

Formula: sid day = yr × 365.999337044

Reverse: yr = sid day × 0.0027322454

Step-by-Step Example

Start with your value in Year (365 days). For example: 5 yr
Multiply by the conversion factor: 5 x 365.999337044
The result is: 1,829.996685 sid day

About Year (365 days)

The year (365 days) (yr) is a unit of time. One year (365 days) equals 3.153600 × 10^+7 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: time calculations, engineering and science, education.

About Sidereal Day

The sidereal day (sid day) is a unit of time. One sidereal day equals 86164.0905 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: time calculations, engineering and science, education.

Frequently Asked Questions

How many Sidereal Day are in 1 Year (365 days)?

There are exactly 365.999337044 Sidereal Day in 1 Year (365 days). This means the conversion factor from Year (365 days) to Sidereal Day is 365.999337044.

What is the formula to convert Year (365 days) to Sidereal Day?

The formula to convert Year (365 days) to Sidereal Day is: sid day = yr × 365.999337044. For example, to convert 10 Year (365 days) to Sidereal Day, you would multiply 10 by 365.999337044.

What is a Year (365 days)?