♂ Free Mars Return Calculator: Every Pass, Direct and Retrograde

Umbriel's free Mars return calculator finds the exact dates Mars comes back to the degree it held at your birth, roughly every two years.

A Mars return is Mars arriving back at the degree of the zodiac it occupied when you were born. Mars takes 687 days, a little under two years, to go round the Sun, and Earth's own motion makes it loop backwards for a couple of months about every two years. Read as a restart of drive: what you go after, how you fight and how you spend your energy, in the part of the chart natal Mars occupies. It is a reflective reading, not a forecast.

Mars is the first planet outside Earth's orbit, so its loop backwards (the retrograde) comes when Earth overtakes it, and a return that falls in that loop is crossed three times.

The detail a single date leaves out is that the return is not always one moment. Mars retrogrades, so it can cross your degree, back over it, and cross a third time: three exact passes, and every one of them is exact. Umbriel lists every crossing in the window it searches, labels each direct or retrograde, and says which one the return is dated from. Many return calculators give one date; this page does not say what any particular one does, because we have not audited them. It says what Umbriel does and why one date can be too little.

• Mars's own lap of the Sun is 687 days, but that is the lap Umbriel does not use here.
• What Umbriel computes: the return to your tropical zodiac degree as seen from Earth, found by scanning the sky for every crossing of that degree.
• Measured on Umbriel's own engine across 36 natal degrees: 565 complete Mars returns, consecutive returns of one degree 522 to 712 days apart, 686 days on average.
• 4 in every 100 of those returns had more than one exact pass; the longest ran 169 days from first pass to last.

Take someone born on 8 July 1976 at 09:30 UT. This is an invented birth, not anyone's chart. Their natal Mars is at 0.87° Virgo. Searching from 1 June 2026 to 1 March 2028, Umbriel finds one complete Mars return with 3 exact passes:

The return is dated from the first pass, 28 November 2026, 04:20 UT, but Mars crosses the same degree again going backwards on 19 February 2027, 09:46 UT and a third time going forwards on 16 May 2027, 22:01 UT. From first pass to last is 170 days. A calculator that printed only the first date would leave out the other two exact hits.

This tool finds the moments Mars comes back to the tropical longitude it held at your birth. Your natal Mars is computed first, as a tropical longitude, even if your chart is set to sidereal, so the dates are never shifted by the ayanamsa. Umbriel then scans forward from today for 2.3 years (1.2 times Mars's geocentric period of 1.8808 years in the code), sampling Mars's position in steps of at most 4.7 days. Wherever the position crosses your natal degree it halves the interval 40 times to pin the moment. Crossings are grouped into one return when they fall within a quarter of a period of each other (about 172 days), because Mars can retrograde back over the degree and cross it three times. The table lists each return dated from its first pass, every pass with its date and time, and marks a return as partial if a pass falls outside the window searched. Mars's position comes from compact orbital elements (Kepler's equation solved for the moment asked), not from the VSOP87D series the outer planets use, so it is less precise on paper than Jupiter's; the accuracy page quotes under 0.2 degrees against published ingress dates, and for return dates the page records a comparison with NASA/JPL Horizons. Mars's own lap of the Sun is 687 days. The dates depend on your birth moment only through your natal Mars, but the house it is in needs a birth time. The table shows the next return and the ones after it that fall in the window, not every return since birth.

On 12 October 2026 Umbriel's Mars return dates were compared with NASA/JPL Horizons (DE441, apparent geocentric ecliptic longitude of date): the body's position at the birth moment gave the target degree, a daily then hourly table from Horizons located every crossing, and each was set beside the engine's. For 3 invented births that was 11 exact passes, and the largest difference was 44 minutes. What was not checked: returns before 2005 or after 2055, charts cast for the return moment (houses and angles), any birth place, and the sidereal zodiac (return dates are always tropical). Other planets' returns have their own checks and are not covered by this one.