Mercury Sign Calculator

Enter your birthday to find your Mercury sign and whether Mercury was retrograde.

Your Mercury sign is the zodiac sign the planet Mercury was in when you were born. Astrologers read it as how you think, learn and speak. It is always either your Sun sign or the sign next to it, because Mercury never strays far from the Sun. To find it, you only need your date of birth.

How the calculator works

The calculator finds where Mercury appeared from Earth, against the zodiac, at the moment you were born. It gives the sign, the degree, the dates Mercury entered and left that sign, and whether it was moving forward or retrograde.

We checked our Mercury positions against NASA's Jet Propulsion Laboratory at 9 dates between 1950 and 2030. The largest gap was 3.4 arcseconds, less than a thousandth of a degree. The comparison is on the method page.

Why your Mercury sign is close to your Sun sign

Mercury is the innermost planet, and from Earth it is never seen more than 27.8 degrees of the zodiac from the Sun. A sign is 30 degrees wide. So Mercury is in the Sun's sign on 51% of days and in a neighbouring sign on the other 49%. It is never two signs away.

How long Mercury stays in a sign

A typical stay is 19 days. When Mercury turns retrograde inside a sign it stays much longer: the longest between 1930 and 2040 was 69 days in Cancer, from June 1, 1934 to August 9, 1934.

Mercury retrograde

About three times a year, Mercury passes between Earth and the Sun and overtakes us on the inside track. For 20 to 24 days it appears to move backward through the zodiac. Nothing changes in Mercury's actual orbit. It is an effect of watching a faster planet lap us on the inside: on the near side of its loop, Mercury crosses our view in the opposite direction.

Between 1930 and 2040 there are 350 Mercury retrogrades, 3.2 a year on average, covering 19% of all days. About one person in 5 is born during one. Astrologers read a natal Mercury retrograde as a mind that works inward first: reflective, original, sometimes slower to speak, and inclined to revisit a thought before settling it.

Mercury retrograde dates

Each row runs from the day Mercury turned retrograde to the day it turned direct. If your birthday falls inside a row, you were born with Mercury retrograde. Dates are in Universal Time.

A worked example

Take someone born on June 15, 1995. Mercury was at 9°55′ Gemini that day, moving retrograde. It was in Gemini from May 2, 1995 to July 10, 1995, a stay of 69 days. That is the same sign as the Sun. The retrograde ran from May 24, 1995 to June 17, 1995.

Mercury was 14 degrees behind the Sun, so it rose before the Sun, as a morning star. Some astrologers read a morning-star Mercury as a mind that runs ahead of events, and an evening-star Mercury as one that reflects on them afterward.

Mercury sign dates for 2026 and 2027

These are the dates Mercury moves from sign to sign, in Universal Time.

What each Mercury sign means

These are the traditional readings of Mercury by sign. Mercury is at home in Gemini and Virgo, the two signs it rules, and is thought least comfortable in the signs opposite them, Sagittarius and Pisces.

Reviewed by Natal Points. Tables and figures on this page were calculated in October 2026.