Mars sign calculator
Mars is your drive: how you go after what you want, what makes you angry, how desire shows up. It spends about six weeks in a sign, and sometimes much longer, so your birth date is usually all it takes.
- Mars sign & degreeThe sign Mars was in when you were born, to the degree.
- Sign-change checkIf Mars changed sign around your birthday we say so and give the moment it did.
- Retrograde flagWhether Mars was retrograde at your birth (about one person in ten).
- What it meansA short reading of your Mars sign and a link to the full page about it.
How it’s calculated
Mars takes about two years to go round the zodiac, usually six to seven weeks per sign. Every two years or so it turns retrograde for about ten weeks, and in those years it can stay in one sign for six months or more.
We calculate Mars’s apparent position with our own ephemeris code (astronomy-engine underneath, checked against Swiss Ephemeris). To decide whether your birth date alone is enough, we check every hour of that date in every time zone, from UTC−12 to UTC+14.
When Mars stays in one sign across that window, the answer is certain. When it changes sign inside it, the result shows both signs and the moment of the ingress; add your birth time and city and we work out which side of the line you were born on.
Mars in the twelve signs
- Mars in Ariesfirst through the door · anger that flares and fades
- Mars in Taurusslow to anger, slower to forgive · works until it’s done
- Mars in Geminiwins arguments on points · flirts by text
- Mars in Cancerfierce for family · anger turns into moods
- Mars in Leoplays to an audience · proud to a fault
- Mars in Virgofixes what others ignore · anger comes out as critique
- Mars in Libraargues for fairness · charming under pressure
- Mars in Scorpioplays the long game · remembers everything
- Mars in Sagittariusblunt, then laughs about it · needs room to roam
- Mars in Capricornambitious and patient · cool head in a crisis
- Mars in Aquariusquestions every rule · cool in an argument
- Mars in Piscesacts on intuition · avoids open conflict
Asked often
What does my Mars sign mean?
Mars is read as how you act: your energy, ambition, temper, courage and desire. Mars in a fire sign tends to act first and think later; in an earth sign it works steadily; in air it argues and plans; in water it acts on feeling and protects its own.
Can my Mars sign be far from my Sun sign?
Yes. Unlike Mercury and Venus, which stay close to the Sun, Mars can be in any sign relative to your Sun, so it often adds a very different note to your chart.
Why does Mars sometimes stay in a sign for months?
Because of its retrograde. Seen from Earth, Mars appears to slow down, back up for about ten weeks and then move forward again. In those years it can spend half a year or more in one sign, and many people born months apart share the same Mars sign.
Do I need my birth time?
Rarely. Mars changes sign only every six weeks or so. If it changed sign on or near your birthday, the calculator flags it and asks for the time and city.
What is Mars in compatibility?
Astrologers look at how one person’s Mars meets the other’s Venus (attraction), Moon (how energy and feelings mix) and Mars (how you handle conflict together). Our free compatibility calculator lists those contacts for two charts.
Desire, drive and the two of you
The compatibility report reads how your Mars meets someone else’s Venus, Moon and Mars. The natal chart book gives Mars its own chapter, read with the rest of your chart.
Other free calculators
- Compatibility calculatorTwo birth charts, side by side
- Personal horoscopeYour transits for the next 30 days
- Venus sign calculatorLove style and taste, from your birth date
- Mercury sign calculatorHow you think and talk, from your birth date
- Birth chart calculatorCalculate your birth chart
- Moon sign calculatorFind your Moon sign
- Rising sign calculatorFind your Rising sign
- Sky calendarCalendars by year: 2026–2028
- Planets in the signsTen planets, twelve signs: the full guide