Mars in the 11th house puts the planet of heat and conflict in the room of friends, groups and hopes. Most guides stop at the fighter for a cause. We asked a plainer question first. When are people born with it? The answer is mostly by day. On a U.S. hospital clock, about three in four people with Mars in the 11th house were born with the Sun above the horizon. Born in the 9 a.m. hour, you have about a one in seven chance of having it. Born in the 9 p.m. hour, the chance falls to one in thirty-three.
That day bias matters for a reason older than any chart app. The Greek astrologers split the planets into a day team and a night team. Mars plays for the night. So a Mars in the 11th house is, most of the time, a night planet at work in a day chart. The old books called that the harsher Mars. This guide shows our count first, then what the old and new astrologers say Mars does in this room.
A harsh planet in the room of the Good Spirit
A birth chart is a map of the sky at the moment you were born. The houses are twelve slices of that sky. Each slice covers one part of life. The 11th house covers friends, allies, groups, hopes and the help that comes to you through other people.
The Greek astrologers had a warmer name for it. They called it the Good Spirit, Agathos Daimon in Greek. Vettius Valens, who wrote his Anthologies in the second century, uses that name. So does Paulus Alexandrinus, two centuries later. For them, this was a room of luck and gifts, and friends were only one part of it. Our guide to 11th house astrology and its old name tells the full story of the room.
The Greeks also gave each planet one house where it was glad to be. They called that house its joy. The list comes from Firmicus Maternus, in book two of his Mathesis, and from Paulus. Mercury rejoices in the 1st house, the Moon in the 3rd and Venus in the 5th. Mars rejoices in the 6th. The Sun rejoices in the 9th, Jupiter in the 11th and Saturn in the 12th.
So the 11th house is the joy of Jupiter. The old books call Jupiter the greater benefic, which means the planet that does the most good. They call Mars a malefic, which means a planet that brings harm when it is out of place. Mars in the 11th house is a harsh guest in the home of the kindest planet. Our page on Jupiter in the 11th house covers the host.
Where Mars sits in the sky
The houses are a real place in your birth sky. The 1st house starts at the eastern horizon, where planets rise. The 10th house starts near the top of the sky. The 12th and the 11th fill the climb between the two.
The sky turns from east to west once a day. A planet rises in the east, climbs, crosses the top of the sky and then sets in the west. On its way up, it passes through the 12th house first, then the 11th, then the 10th. So Mars in the 11th house means one thing in the sky. At the minute you were born, Mars was high in the eastern sky. It had risen some two to four hours before.
The Sun gives the easy case. The Sun sits in the 11th house in the morning, near 8 a.m. to 10 a.m. by the Sun. Our guide to the Sun in the 11th house shows that window city by city. Mars keeps the same rule, but on its own clock.
Day team, night team
Ptolemy, in his Tetrabiblos, sorts the planets into two teams. The Greek word for such a team is hairesis. Modern authors call it sect. The Sun, Jupiter and Saturn lead the day team. The Moon, Venus and Mars lead the night team.
A chart is a day chart when the Sun is above the horizon at birth. It is a night chart when the Sun is below it. A planet is said to be in sect when it belongs to the team of the chart. A day planet in a day chart is in sect. A night planet in a day chart is out of sect.
For the two malefics, this was a big deal. The Hellenistic authors held that a malefic out of sect does the most harm. Chris Brennan, who wrote a long modern study of Hellenistic astrology, calls it the most difficult planet in the chart. Mars in a day chart is that planet. Its heat has no night to cool it.
Look again at the joys. The day planets have theirs above the horizon, in the 9th, 11th and 12th. The night planets have theirs below, in the 3rd, 5th and 6th. Our guide to Mars in the 6th house shows the night planet at home under the ground. The 11th house sits on the other side of the sky, in a room built for the day team. So the question for this placement is simple. What share of Mars in the 11th house charts are day charts? We counted.
Why the Mars cycle sets the hour
Mars does not keep one hour. It moves around the sky compared with the Sun. The Earth laps Mars once every 780 days on average. That lap is the synodic cycle, which means the cycle of Mars as seen from Earth. Our guide to Mars in the 1st house walks through that cycle stage by stage.
Two stages matter most here. At conjunction, Mars sits behind the Sun and keeps the Sun’s hours. It sits in the 11th house in the morning, like the Sun, and the Sun is up. At opposition, Mars sits across the sky from the Sun. It rises at sunset. It then sits in the 11th house in the late evening, and the Sun is down.
Now the key fact. Mars spends most of its cycle near the Sun, on the far side of it. In our count from 1940 to 2030, Mars sat within 60 degrees of the Sun 52.9 percent of the time. It sat within 30 degrees of the opposition point only 5.9 percent of the time. So most of the time, Mars keeps hours close to the Sun’s hours. That pulls its 11th house window into the morning and the day.
The clock, hour by hour
Here is the chance of Mars in the 11th house for each hour on the clock. It covers births in 36 large U.S. metro areas, weighted by their size. It uses Placidus houses, the system most U.S. charts use. The hours are local clock time, with daylight saving time applied.
| Birth hour on the clock | Chance of Mars in the 11th house. |
|---|---|
| Midnight to 1 a.m. | 4.0 percent, about 1 in 25. |
| 3 a.m. to 4 a.m. | 7.7 percent, about 1 in 13. |
| 6 a.m. to 7 a.m. | 12.4 percent, about 1 in 8. |
| 8 a.m. to 9 a.m. | 13.5 percent, about 1 in 7. |
| 9 a.m. to 11 a.m. | 13.8 percent, about 1 in 7. |
| Noon to 1 p.m. | 13.3 percent, about 1 in 8. |
| 2 p.m. to 3 p.m. | 10.9 percent, about 1 in 9. |
| 4 p.m. to 5 p.m. | 7.2 percent, about 1 in 14. |
| 6 p.m. to 7 p.m. | 4.4 percent, about 1 in 23. |
| 9 p.m. to 10 p.m. | 3.0 percent, about 1 in 33. |
| 11 p.m. to midnight. | 3.4 percent, about 1 in 29. |
The high point is the late morning, from 9 a.m. to 11 a.m. The low point is the 9 p.m. hour. The top is more than four times the bottom. The shape is the Sun’s own 11th house hours, spread out on each side.
The clock time here is not sun time. In summer, daylight saving time moves the clock one hour ahead of the sky. That is one reason the peak runs past 10 a.m. and not only from 8 a.m. to 10 a.m.
Real birth hours make it more common
Babies are not born evenly across the day. Hospitals book planned births, and those land in working hours. To test this, we used the CDC natality file 2024. It is the full U.S. birth record for that year, with 3,638,436 births, nearly all with a time of birth. The busiest hour is 8 a.m., with 6.27 percent of all births. The small hours are the quietest, near 3 percent each. Cesarean births, where the baby is delivered by surgery, peak hard at 8 a.m.
This time the two clocks agree. Mars in the 11th house peaks in the morning, and so does the maternity ward. We ran the count twice. First, every clock minute had the same weight. Then each minute was weighted by its real share in the CDC file.
| Birth hours used | Placidus houses | Whole sign houses. |
|---|---|---|
| Every hour equal | 8.44 percent | 8.60 percent. |
| Real U.S. birth hours, all days | 8.93 percent | 9.20 percent. |
| Real hours, weekdays | 9.01 percent | 9.30 percent. |
| Real hours, weekends | 8.66 percent | 8.83 percent. |
| Cesarean births | 9.93 percent | 10.19 percent. |
| Vaginal births | 8.46 percent | 8.73 percent. |
| Births after labor was started with drugs | 8.26 percent | 8.65 percent. |
A plain chance of one in twelve is 8.33 percent. On a U.S. hospital clock, Mars in the 11th house runs above that, at 8.93 percent under Placidus. That is about one birth in eleven. Cesarean babies come first, at 9.93 percent, or about one in ten. Their 8 a.m. peak sits in one of the best hours for this placement.
The lift is smaller than for the Sun. Our Sun in the 11th house count found 10.51 percent with the same CDC hours. The Sun is in the 11th house every morning. Mars is there in the morning only when it sits near the Sun, which is about half the time.
Three in four are born by day
Now back to sect. We counted how many Mars in the 11th house charts are day charts, with the Sun above the horizon at the same minute.
| Birth hours used | Day births, Placidus | Day births, whole sign. |
|---|---|---|
| Every hour equal | 65.5 percent | 68.8 percent. |
| Real U.S. birth hours, all days | 74.3 percent | 76.8 percent. |
| Real hours, weekdays | 75.8 percent | 78.1 percent. |
| Real hours, weekends | 68.7 percent | 71.8 percent. |
| Cesarean births | 84.1 percent | 85.4 percent. |
With every hour equal, about two in three Mars in the 11th house charts are day charts. That follows from the sky alone. Mars spends most of its cycle near the Sun, so both climb the eastern sky together.
The hospital clock pushes that share to three in four. It adds morning births, when Mars in the 11th house comes with a Sun that is up. For cesarean babies, the share reaches five in six. So a U.S. baby born by planned surgery with Mars in the 11th house almost always gets the day version. In the old terms, that is Mars out of sect.
What the Mars cycle does to your odds
With every hour equal, the stage of the Mars cycle makes almost no difference. The share stays between 8.3 and 8.6 percent under Placidus at every stage. The 11th house moves around the clock, but it always takes about the same slice of the day.
With real birth hours, the stage makes a big difference. Here are the results in time order, starting when Mars passes behind the Sun.
| Stage of the Mars cycle | When Mars is in the 11th house | All real U.S. births | Cesarean births only. |
|---|---|---|---|
| Just after Mars passes behind the Sun | Early morning, a day chart | 10.7 percent | 16.8 percent. |
| Morning sky, 30 to 90 degrees from the Sun | Before dawn to early morning | 6.1 to 7.5 percent | 3.8 to 8.1 percent. |
| Morning sky, 90 to 150 degrees from the Sun | After midnight, a night chart | 6.3 to 6.8 percent | 3.9 to 4.6 percent. |
| Around opposition | Late evening, a night chart | 7.5 to 8.0 percent | 5.8 to 6.5 percent. |
| Evening sky, 90 to 150 degrees from the Sun | Late afternoon to early evening | 8.8 to 9.6 percent | 7.4 to 8.7 percent. |
| Evening sky, 30 to 90 degrees from the Sun | Midday to mid afternoon, a day chart | 10.0 to 10.8 percent | 10.3 to 13.2 percent. |
| Mars closing in on the Sun again | Mid morning, a day chart | 10.2 percent | 13.5 percent. |
The weeks just after Mars passes the Sun are the richest. Mars then rises shortly before the Sun and climbs into the 11th house during the 8 a.m. rush. In that stage, 16.8 percent of cesarean babies get it, about one in six. And the stage is long. Mars moves slowly against the Sun then, so it lasts for months.
The short stages around opposition push the other way. There, Mars in the 11th house falls in the late evening and the night. Few planned births happen then. But those stages are brief, so they pull the total down only a little.
This is the mirror of our Mars in the 5th house count. The 5th and the 11th sit opposite each other in the sky, twelve hours apart on the clock. The stages that fill one on a busy ward are the stages that empty the other.
Five real days in New York
To make this concrete, we computed the exact clock window for a birth in New York City on five dates. We used Placidus houses and New York clock time.
On 9 January 2026, Mars was behind the Sun. Mars sat in the 11th house from 8:58 a.m. to 10:31 a.m. Eastern Standard Time. It was a day chart, in the busiest hours of the ward.
On 10 June 2026, Mars was in the morning sky, 33 degrees from the Sun. The window ran from 5:58 a.m. to 8:18 a.m. Eastern Daylight Time. The Sun rose near 5:25 a.m., so it was a day chart.
On 26 September 2026, Mars is in the morning sky, 64 degrees from the Sun. The window runs from 3:51 a.m. to 6:15 a.m. Eastern Daylight Time. The Sun rises near 6:48 a.m., so this is a night chart. It is the in sect version, and it comes before the ward gets busy.
On 19 February 2027, Mars reaches opposition. The window runs from 7:42 p.m. to 9:55 p.m. Eastern Standard Time. That is a night chart again.
On 1 July 2027, Mars will be in the evening sky, 73 degrees from the Sun. The window runs from 1:44 p.m. to 3:47 p.m. Eastern Daylight Time. That is a day chart.
Each window lasts about two hours. That is why the house needs an exact birth time. A time rounded to the hour can move Mars in or out of the 11th house.
Two house systems, two answers
Astrologers split the sky into houses in more than one way. In whole sign houses, each house is one full sign. Count ten signs on from your rising sign, and that sign is your 11th house. This is the oldest system on record. Chris Brennan argues that it was the standard method of the Greek authors, and Demetra George uses it in her books on the old tradition.
In Placidus houses, each house is a slice of time. Each point of the sky takes the same share of its day arc to cross each house above the horizon. Most U.S. software uses Placidus by default.
On 19 February 2027 in New York, Placidus puts Mars in the 11th house from 7:42 p.m. to 9:55 p.m. Whole sign puts it there from 10:29 p.m. to about 1 a.m. the next day. The two windows do not overlap at all. If your chart shows Mars in the 10th or the 12th house, the house system is the first thing to check.
Whole sign gives a higher share, 9.20 percent with real hours. Its 11th house window comes a little later in the morning on average, and those are busy hours on the ward.
Morning star or evening star
The old authors asked one more question. Did Mars rise before the Sun or after it? A planet that rises before the Sun is called oriental, which means eastern. William Lilly, in Christian Astrology in 1647, gives Mars two extra points of strength when it is oriental. In his table, a planet in the 11th house gains four points, one of the best scores for a house.
So we split the count again. With every hour equal, Mars in the 11th house is oriental 49.9 percent of the time, about half. With real U.S. birth hours, it falls to 44.0 percent. Most morning sky stages put Mars in the 11th house before dawn, when few babies are born. The evening sky stages put it near midday, in busy hours.
What the old texts say about Mars here
The old reading starts from the house topics. The 11th house holds friends, patrons, hopes and gains. Mars stands for heat, iron, quarrels and soldiers. Put them together, and the old authors saw friends of a sharp kind. They saw allies made in a fight, gains won by force and hopes chased with haste.
The 11th is a good house in every old list. Mars there was not a disaster in their eyes. A malefic in a good place was read as harm softened by the room. But the joy of Jupiter is not the joy of Mars. The Greek authors read the guest as at odds with its host. Sect adds the second layer. By day, Mars is out of sect, and the tradition reads the heat as rougher. By night, Mars is in sect, and the heat is read as more useful.
Our count gives that old split a new weight. With every hour equal, two in three natives get the day version. On a U.S. hospital clock, three in four do. Among cesarean babies, five in six do.
These are judgments from a symbolic craft, not measured facts. We give them so you know where the claims you read come from.
What modern astrologers read into it
Modern writers move the focus from events to the inner life. Stephen Arroyo reads Mars as the way you go after what you want. In the 11th house, the want is a shared goal. You fight for the team, the club or the cause.
Liz Greene treats Mars as the urge to stand apart as your own person. In the room of groups, that urge sits in tension with the wish to belong. You want to be part of the crowd and to lead it at the same time. Robert Hand reads houses as fields of life where a planet acts. Mars in the field of friends acts through teams, rivalries and bold group projects.
Demetra George, who works from the Greek sources, keeps the old question in view. Is Mars in your chart a day Mars or a night Mars? Her answer shapes how much heat she expects the placement to carry. For this house, our count says the answer is day for most U.S. births.
How it can show up in a life
Every chart is more than one placement. Read these as patterns to test, not verdicts.
- The organizer. When a group stalls, you are the one who sets the plan.
- Friends made in a fight. Your closest bonds grew out of a shared cause or a shared rival.
- A cause to defend. You join the campaign, the union or the protest, and you stay for the hard part.
- Rivals inside the team. You compete with the people you work beside, and it spurs you on.
- Big hopes, chased fast. You set a goal for the future and move on it now.
The hard side is the same heat turned up too far. A debate turns into a split. A group chat turns into a feud. Friends drop away when the cause changes. The work is to keep the fire aimed at the goal and away from the people who share it.
The neighbors differ. For a kind planet in this same room, our page on Venus in the 11th house tells a very different story. And Mars in the 1st house shows the same planet just before it rises.
How to check your own chart
You need three things: your birth date, your birth place and your exact birth time. The time on a U.S. birth certificate is the local clock time, with daylight saving time if it was in force. Chart software converts clock time to sky time for you, so enter the clock time as written.
Then check two things. First, which house system your chart uses. If Mars sits near the edge of the 11th house, try both systems. Second, check where the Sun sits. If the Sun is in houses 7 to 12, you have a day chart. If it is in houses 1 to 6, you have a night chart. That tells you which Mars the old authors would read for you.
How we measured this
We want these numbers to be checkable, so here is the method in full.
Places: the same 36 large U.S. metro areas as our other Mars house counts, from New York to San Jose, weighted by 2020 population. Each has its own time zone. Phoenix keeps standard time all year.
Dates: a regular grid of 8,885 dates, one every 3.7 days from 1940 to 2030. The step is not a whole number of days, so the grid does not keep landing on the same weekday. Within each date, one clock time every ten minutes. We applied today’s daylight saving rule to every date, so each hour means the same clock hour a U.S. parent would read.
Birth hours: either every hour equal, or each ten minute slot weighted by its share in the CDC natality file 2024, for all births and for each type of birth.
Sky positions: the Swiss Ephemeris, in its built-in Moshier mode. Houses: Placidus and whole sign, from our own house code. It matched the Swiss Ephemeris house routine within 0.01 degree on 3,000 test charts. Day or night: the Sun above or below the horizon at the same minute. Oriental: Mars west of the Sun, so that it rises first.
Check one: a second count on 150,000 random charts per case, drawn with a fixed seed. Each chart was cast by the Swiss Ephemeris house routine. It gave 8.48, 9.00 and 10.01 percent under Placidus for even hours, real hours and cesarean births. It gave day shares of 66, 74 and 84 percent. All sit within one margin of error of the main count.
Check two: a second library, astronomy-engine, placed Mars within 0.01 degree of the Swiss Ephemeris on 2,000 test dates.
Check three: a long window. We reran the grid on 12,541 dates from 1600 to 2400, one every 23.3 days. Under Placidus, it gave 8.41 percent with even hours, 8.91 percent with real hours and 9.93 percent for cesarean births. The day share stayed at 74.4 percent with real hours. The findings hold on the long run.
One limit is worth saying plainly. The CDC hours are from 2024. Births in 1950 were not timed by surgery plans the way they are now. For an older reader, the true figure sits between the even-hours row and the real-hours row.
Questions people ask
How common is Mars in the 11th house?
For U.S. births, about 8.9 percent under Placidus houses and 9.2 percent under whole sign houses, using real birth hours. That is about one chart in eleven. With every hour equal, it would be 8.4 percent.
What birth time gives Mars in the 11th house?
Any time can, because the window moves through the day with the Mars cycle. On average, the most likely hours are 9 a.m. to 11 a.m., at 13.8 percent. The least likely is 9 p.m. to 10 p.m., at 3.0 percent.
Is Mars in the 11th house above or below the horizon?
Above it. The 11th house is the stretch of sky high in the east. Mars there rose some two to four hours before your birth and has not yet reached the top of its path.
Is Mars bad in the 11th house?
The old books call Mars a malefic, and the 11th house is the joy of Jupiter. So they read it as a harsh guest in a kind room. The room is a good one, which softens it. With real U.S. birth hours, 74.3 percent of people with it are day births, the version the tradition reads as harsher.
Are cesarean babies more likely to have Mars in the 11th house?
Yes. They land at 9.93 percent, about one in ten. In the months just after Mars passes the Sun, up to one cesarean baby in six gets it.
Why does my chart show Mars in the 10th or 12th house instead?
Most likely your chart uses a different house system, or the birth time differs by a few minutes. Each window lasts about two hours, and Placidus and whole sign can disagree by an hour or more.
What to take from it
Mars in the 11th house is a morning and midday placement. It is more than four times likelier at 10 a.m. than at 9 p.m., because Mars spends most of its cycle near the Sun. The 8 a.m. rush of planned births works for it, so on a U.S. hospital clock it rises to about one birth in eleven.
The old books saw a harsh planet in the joy of Jupiter, and they asked one question first: was the birth by day or by night? For three in four people with this placement, the answer is day, the version the tradition read as the harder Mars. Check your own chart for the Sun’s place before you read any verdict.
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