Declination to Decimal Degrees Converter

How it is calculated

Declination is the angle of a point on the sky north or south of the celestial equator, written as degrees, arcminutes and arcseconds. The tool joins them into one decimal number: decimal = D + M ÷ 60 + S ÷ 3600, because there are 60 arcminutes in a degree and 60 arcseconds in an arcminute (3600 in a degree). The sign comes from the direction selector (north positive, south negative) or from a minus typed on the degrees, including "-0"; minutes and seconds are entered as positive numbers and may be left empty (counted as 0). The result has six decimals and the DMS is echoed back with a north/south note. Input is validated: minutes and seconds must be under 60, degrees must be whole when minutes or seconds follow, and the total cannot exceed 90°. Anything else shows no result.

Common mistakes

• Typing the sign in front of the degrees and also choosing south. Either one makes the value negative; doing both still gives a single negative sign, not a double negative that turns positive.
• Forgetting the sign when the degrees are zero. A declination like -0° 30′ is south, so type "-0" or choose south, otherwise the result is positive.
• Putting a minus on the minutes or seconds. They must be positive, and 60 or more is rejected, so 75 minutes must be written as 1° 15′ before entering.
• Typing decimal degrees together with minutes, such as 23.5° 30′. Fractional degrees are only accepted on their own; mixed with minutes there is no result.
• Mixing up declination with right ascension. Right ascension comes in hours, minutes and seconds, and one hour is 15 degrees, so do not enter it here.