2027 Forecast

House overlays

Synastry house overlays show where a partner's planets land in your chart. Any given house has a 54.3% chance of holding at least one of them — before any meaning is involved.

Each overlay: house 1, house 2, house 3, house 4, house 5, house 6, house 7, house 8, house 9, house 10, house 11 and house 12.

Synastry House Overlays: All 12, and the Odds of Each

Arithmetic first

Half of all strangers occupy your eighth house

8.33% chance one planet lands in a given house — each house is 30° of 360.
54.3% chance at least one of their nine planets is there. More often than not.
16.9% chance of two or more — the case usually described as a strong emphasis.

An eighth-house overlay gets written up as a rare karmic bond. It occurs in 54.3% of random pairings, because nine planets spread over twelve houses leave about half of them — 6.5 of the twelve on average — occupied by someone. The expected number of their planets in any one of your houses is 0.75.

That does not make the reading empty — it means the useful detail is which planet and how close to the cusp, not whether the house is filled.

How many of a partner’s nine planets land in one given house of yours
How many of a partner’s nine planets land in one given house of yours How many of a partner’s nine planets land in one given house of yours: 0 planets 45.7%, 1 planet 37.4%, 2 planets 13.6%, 3 planets 2.9%, 4 or more 0.4%. 0%30%60%0 planets: 45.7%45.7%0 planets1 planet: 37.4%37.4%1 planet2 planets: 13.6%13.6%2 planets3 planets: 2.9%2.9%3 planets4 or more: 0.4%0.4%4 or moreSource: binomial odds, 9 planets, 1 in 12 per houseastrohot.com 0%30%60%0 planets: 45.7%45.7%0 planets1 planet: 37.4%37.4%1 planet2 planets: 13.6%13.6%2 planets3 planets: 2.9%2.9%3 planets4 or more: 0.4%0.4%4 or moreSource: binomial odds, 9 planets, 1 in 12 per houseastrohot.com

Empty is the single most likely outcome, at 45.7%, but the other 54.3% has someone in the house; three or more planets together come up 3.3% of the time.

Houses are the most time-sensitive thing in a chart

The ascendant advances one degree every four minutes, and a house spans thirty degrees. So an error in the birth time moves the entire grid:

Error in birth timeAscendant shiftsHouses shift
15 min 3.8° 0.13 houses
30 min 7.5° 0.25 houses
60 min 15° 0.5 houses
120 min 30° 1 house
240 min 60° 2 houses

Two hours out and every planet moves to the next house along — the eighth-house reading you were given becomes the seventh or the ninth. Most people know their birth time to the nearest hour at best, and hospital records round. This is the single strongest reason to treat house overlays as the least reliable layer of a synastry reading, and it is almost never stated.

Aspects between planets do not have this problem — only the Moon and the ascendant move fast enough to matter. Aspects →

Most asked-about first

All twelve, by how often they are asked about

The order is telling: the twelfth and eighth beat the seventh, which is the house tradition assigns to partnership. People ask about the hidden and the heavy, not about the one that is supposed to be the subject.

HouseCovers
12 what is hidden, dissolved or carried unconsciously
8 shared resources, exposure and what is not said aloud
7 partnership as an arrangement
5 romance, play and creative output
1 first impressions and self-presentation
4 home, family and the private self
2 money, possessions and self-worth
10 public standing and direction of work
11 friendship, groups and shared aims
3 everyday talk and thinking
9 belief, distance and what you consider true
6 routine, work and health

Cite this page

AstroHot. “Synastry House Overlays: All 12, and the Odds of Each.” Accessed October 31, 2026. https://astrohot.com/synastry/houses/

For Wikipedia {{cite web |title=Synastry House Overlays: All 12, and the Odds of Each |url=https://astrohot.com/synastry/houses/ |website=AstroHot |access-date=2026-10-31}}