Do zodiac signs predict whether a relationship lasts?

In this analysis, compatibility scores were compared between couples still together and couples who separated. The method, the sample size and the result are published in full above. A sample of a few dozen couples cannot detect a small effect, so the finding is limited to this list and these systems rather than to astrology in general.

How was celebrity couple compatibility calculated?

Each couple's two birth dates were run through the same zodiac and numerology engines that power the calculators on this site. The zodiac engine scores aspect, element, modality and ruling planet. The numerology engine scores life path trait similarity plus traditional affinity. The blended figure is the mean of the two.

Can the results be reproduced?

Yes. Both engines are live on the site, so entering the same two birth dates into the public calculators returns the same numbers used in the analysis. No score was adjusted after the fact and no couple was excluded.

Why are celebrity couples not a reliable sample?

They are not randomly selected, their separations are reported far more consistently than quiet ones, and their circumstances differ from most relationships. A few dozen couples is also too small to detect a small effect even if one existed.

Is sun sign compatibility a fair test of astrology?

A practising astrologer would say no, since two birth dates without times or places is far short of a full synastry reading. That is a fair objection. It is also exactly what every free compatibility calculator on the internet does, including the ones tested here.

Celebrity Couple Compatibility Study

The finding

Across 177 couples, compatibility scores were effectively identical for those still together (75.8%) and those who separated (74.3%). A difference of 1.4 points is well inside the noise, which means these systems did not distinguish between the two groups at all.

177

couples analysed

still together

separated

Results by system

System	Still together	Separated	Difference
Zodiac compatibility	74.6% ±13.0	74.5% ±12.4	+0.1 within noise
Life path compatibility	76.5% ±15.2	73.6% ±14.7	+2.9 within noise
Both combined	75.8% ±9.5	74.3% ±9.4	+1.4 within noise

Figures are means with standard deviation. Any difference under 3 points is reported as noise rather than as a result, because at this sample size it is.

Two things the systems predict

Couples sharing an element	33% of those together	32% of those separated
Mean age gap	5.5 years together	5.5 years separated

Highest scoring pairs in the sample

Couple	Signs	Life paths	Score	Status
Benedict Cumberbatch & Sophie Hunter	Cancer / Pisces	4 / 8	93%	Together
Charles III & Queen Camilla	Scorpio / Cancer	11 / 9	93%	Together
Orlando Bloom & Miranda Kerr	Capricorn / Taurus	11 / 9	93%	Separated
Kurt Russell & Goldie Hawn	Pisces / Scorpio	9 / 6	92%	Together
Emma Stone & Dave McCary	Scorpio / Cancer	7 / 5	91%	Together

Lowest scoring pairs in the sample

Couple	Signs	Life paths	Score	Status
Jeff Bezos & MacKenzie Scott	Capricorn / Aries	6 / 1	53%	Separated
Heidi Klum & Seal	Gemini / Pisces	9 / 4	54%	Separated
Donald Trump & Ivana Trump	Gemini / Pisces	4 / 9	54%	Separated
Reese Witherspoon & Ryan Phillippe	Aries / Virgo	3 / 4	56%	Separated
Miley Cyrus & Liam Hemsworth	Sagittarius / Capricorn	1 / 6	56%	Separated

Method

Each couple's two birth dates were run through the same zodiac compatibility engine that powers the zodiac calculator on this site. It scores on aspect, element, modality and ruling planet.
The same dates were run through the life path engine, which scores on trait similarity plus traditional numerological affinity.
The blended figure is the mean of the two.
Couples were grouped by current status, and the group means compared.
No scores were adjusted, excluded or rounded after the fact. Every couple in the list is in the analysis.

Sample of 177 couples. Last updated September 26, 2026. Relationship statuses change, and any that have changed since the last update will be wrong until the next one.

What this cannot show

This is not a controlled study and should not be read as one. Celebrity couples are not a random sample of relationships, separations are reported unevenly, and a few dozen couples is nowhere near enough to detect a small effect even if one existed. Nothing here establishes that astrology or numerology do or do not work.

What it does do is apply one consistent method to a fixed list and report whatever comes out, including when the answer is that nothing came out. That is a lower bar than a study and a considerably higher one than the usual version of this article.

Why we ran this

This site has a zodiac compatibility calculator and a numerology compatibility calculator. Both produce a number. Neither has ever been checked against anything.

So we checked. We took a list of real couples with publicly documented birth dates and known relationship outcomes, ran every one of them through both engines without adjusting anything, and compared the couples who are still together against the couples who separated.

If these systems detect something, the couples who lasted should score higher. That is a testable claim, and it is the entire point of the exercise.

What makes this different from the usual version

Articles about celebrity star signs normally work backwards. Pick some famous couples, notice a pattern, write it up. Any set of couples contains a pattern if you are willing to choose which ones to include.

This is fixed in advance instead:

The scoring is not ours to adjust. Both engines were built before this study and are live on the site. Anyone can put the same two birth dates into the calculators and reproduce every number below.
Nobody was excluded. Every couple in the list is in the analysis, including the ones that make the result less tidy.
The conclusion follows the data. The finding below is generated from the numbers rather than written first.
Small differences are labelled as noise. Anything under three points is reported as such rather than presented as a discovery.

How to read a null result

If the two groups scored about the same, that is worth saying plainly rather than dressing up.

It does not prove astrology is wrong. A sample of a few dozen couples cannot detect a small effect, celebrity relationships are not representative of relationships generally, and separations among public figures are reported far more consistently than the quiet ones. All of that is true and all of it limits what can be concluded.

What it does mean is narrower and still useful: on this list, with these systems, the scores carried no information about who stayed together. Anyone claiming otherwise about celebrity couples is welcome to show their method.

Sun sign compatibility is also, by the standards of astrology itself, a thin instrument. A practising astrologer would say two birth dates without times or places is nowhere near a synastry reading. That is a fair objection, and it is also what every free compatibility calculator on the internet actually does, including ours.

What compatibility research does find

For contrast, the things that show up repeatedly in relationship research are unglamorous and have nothing to do with birth dates.

How couples handle conflict, particularly whether they repair afterwards, predicts far more than any trait pairing.
Responsiveness in small everyday moments is the basis of the bird test, and the research behind it is unusually well established.
Agreement on the big practical questions — children, money, where to live — does most of the work, which is what the future proofing test is built on.

None of that is as fun as a star sign chart. It is, however, where the actual signal lives, and it is the reason those three tools exist alongside the astrology ones.

Using this data

The figures above are free to quote with a link back to this page. If you want the underlying couple list or have a correction on a birth date or a relationship status, get in touch and it will be updated. The date of the last revision is shown with the results, and statuses that changed after it will be wrong until the next pass.

Zodiac Compatibility Calculator — one of the two engines used here
Numerology Love Compatibility — the other one
Birthday Compatibility Calculator — both together
Age Gap Calculator — the age gap figures above come from this method
Future Proofing Test — the unromantic version of compatibility