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Mars Sign Calculator
Mars is the planet astrologers read for energy, desire and the way you go after what you want. Your Mars sign is where it stood on the zodiac when you were born. Mars moves slowly, so your birth date and place are almost always enough.
What your Mars sign describes
In astrology, Mars is associated with drive, courage, desire and friction: how you start things, how you compete, how you handle anger and what gets you out of bed. Your Mars sign is read as the style of that energy. Some Mars signs are described as quick and direct, others as slow and steady, others as strategic. None of them is better than another; each has its own strengths and its own blind spots.
Why Mars can stay in one sign for months
Mars usually spends about six weeks in a sign, but when it turns retrograde it can stay in one sign far longer. Between 1950 and 2049 the longest stay was about seven and a half months. That is why many people born within the same season share a Mars sign, and why Mars is often read alongside faster placements such as the Moon and the rising sign.
Mars retrograde
About every twenty-six months Mars appears to move backwards for roughly two and a half months. Over 1950 to 2049 it was retrograde on 9.5% of days, so about one person in ten has Mars retrograde. Astrologers often describe it as energy that works best when it is directed inward first: reviewing, rebuilding, choosing the moment. Your result says whether yours was.
How we calculate it
We convert your birth time to Universal Time with the historical time zone rules of your birthplace, then compute the position of Mars as seen from Earth with Astronomy Engine, in the tropical zodiac. We test it against NASA's JPL Horizons ephemeris on fourteen dates from 1879 to 2021, including two with Mars retrograde and one on which Mars changed sign: every position agrees within a fifth of an arcminute, and the change time is within one minute of Horizons. More on our methodology page.
Keep exploring
Mars is usually read with Venus, the planet of affection. For a longer rhythm in your chart, see when your Saturn return falls. The full birth chart shows the house your Mars falls in and its aspects, and a synastry chart shows where one person's Mars meets another person's planets. In numerology, your expression number looks at the abilities traditionally read in your full birth name.
Mars in each sign
What older texts and today's astrologers say about Mars in each of the twelve signs, with every stay of Mars in the sign from 1960 to 2012.
Questions people ask
Your Mars sign is the zodiac sign Mars occupied at the moment you were born. Mars usually stays in one sign for about six weeks, and up to about seven and a half months when it turns retrograde, so your birth date and place are almost always enough. On fewer than 2% of days from 1950 to 1999 Mars changed sign during the day; if yours was one of them, we show both signs and the time of the change.
Astrologers read Mars as the planet of drive, courage, desire and friction, and the sign as the style of that energy: quick and direct, slow and steady, strategic. Sepharial, in 1910, wrote that Mars "confers a sense of freedom, much ambition and executive ability", speaking of the planet in general. No Mars sign is better than another, and your result describes yours as a prompt for reflection, not a prediction.
In traditional astrology Mars rules Aries and Scorpio. Sepharial put it plainly in 1910: "Mars governs Aries and Scorpio." Modern astrologers often give Scorpio to Pluto as well and keep Mars as the ruler of Aries. Sepharial also wrote that a planet in a sign it governs acts more strongly than usual, so in his scheme Mars in Aries or Scorpio is a strong placement.
Not necessarily. Venus never strays far from the Sun, but Mars can stand anywhere in the zodiac relative to it, so your Mars sign can be any of the twelve. Across every day from 1950 to 2009 we counted each Mars sign on between 6.6% and 9.7% of days, so none is much rarer than another.
About every twenty-six months Mars appears to move backwards for roughly two and a half months. From 1950 to 2049 it was retrograde on 9.5% of days, so about one person in ten was born with Mars retrograde. Astrologers often describe it as energy that works best when it is directed inward first: reviewing, rebuilding, choosing the moment. That is a nuance of style, not a warning. Your result says whether yours was retrograde.
Astrologers have long used ephemerides, printed tables that list where each planet stood on every date. Reading Mars from one takes care: a retrograde loop can make Mars cross the same sign boundary more than once, and the dates need adjusting for your time zone. This calculator does the lookup and the conversion from your date and place, and adds the exact degree.
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