Zodiac Compatibility Calculator
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Compare any two signs, or two birth dates, for a compatibility percentage with romance, friendship and work ratings.
Quick answer: This calculator scores a pair of signs by the angle between them, their elements and their modalities. Pick two signs, or two birth dates, above for a compatibility percentage. For example, Aries and Leo score 87%, a trine between two Fire signs, while Aries and Cancer score 34%, a square between Fire and Water. The result shows how the score was built and rates romance, friendship and work.
Zodiac compatibility
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📐 Formula
Score = 55 + angle points + element points + modality points. The angle is the number of signs apart (0 to 6): same sign +12, 30 degrees -4, sextile +16, square -10, trine +20, quincunx -6, opposition +6. Elements: Fire with Air or Earth with Water +14, same element +10, Fire with Earth or Air with Water -2, Earth with Air -6, Fire with Water -8. Modalities: Cardinal with Mutable +3, Cardinal with Fixed or Fixed with Mutable +2, two Mutable 0, two Cardinal or two Fixed -3.
How to Use the Zodiac Compatibility Calculator
Choose the first person's sign
Pick the sign from the list, or choose a birth month and day and the sign is filled in.
Choose the second person's sign
Do the same for the second person. Both signs are required.
Read the percentage and the breakdown
See the compatibility percentage, a band such as Strong match, and how the number was built from the angle, element and modality.
Check the romance, friendship and work ratings
The three ratings read the same angle for different kinds of relationship. For a birthday on the edge of two signs, check the exact sign with the zodiac sign calculator.
Zodiac compatibility calculator by date of birth
Pick two zodiac signs. If you enter a birth month and day for each person instead, the sign is filled in for you. The calculator gives a compatibility percentage for the pair, shows how the number was built, and rates the match for romance, friendship and work. It uses sun signs, so it works from a date of birth alone, with no birth time. People search for this as "star sign compatibility by date of birth" or "horoscope compatibility by birth date", and it is the same calculation.
How the compatibility percentage is worked out
Astrology has no single official scoring system, so we show ours in full. Every pair starts at 55. Then it gains or loses points for three things: the angle between the two signs, the pairing of their elements, and the pairing of their modalities. The angle is the number of signs apart, which is the traditional way astrologers describe the relationship between two signs. The element and modality pairings follow the usual rules: Fire and Air get along, Earth and Water get along, and two signs of the same modality tend to compete.
| Angle between signs | Points | Pairs that sit at this angle |
|---|---|---|
| Conjunction (same sign) | +12 | Same sign |
| Semi-sextile (30 degrees) | -4 | Aries and Taurus, Taurus and Gemini, and so on |
| Sextile (60 degrees) | +16 | Aries and Gemini, Taurus and Cancer |
| Square (90 degrees) | -10 | Aries and Cancer, Taurus and Leo |
| Trine (120 degrees) | +20 | Aries and Leo, Taurus and Virgo |
| Quincunx (150 degrees) | -6 | Aries and Virgo, Taurus and Libra |
| Opposition (180 degrees) | +6 | Aries and Libra, Taurus and Scorpio |
| Element pairing | Points |
|---|---|
| Fire with Air, or Earth with Water | +14 |
| Same element | +10 |
| Fire with Earth, or Air with Water | -2 |
| Earth with Air | -6 |
| Fire with Water | -8 |
| Modality pairing | Points |
|---|---|
| Cardinal with Mutable | +3 |
| Cardinal with Fixed, or Fixed with Mutable | +2 |
| Mutable with Mutable | 0 |
| Cardinal with Cardinal, or Fixed with Fixed | -3 |
The three adjustments are the page's own scoring rules, in plain numbers, and not a published astrological standard. The pairs that gain the most are trines (the same element, four signs apart) and sextiles (compatible elements, two signs apart). The pairs that lose the most are squares, where signs share a modality but have clashing elements. The result box shows the arithmetic for your pair, for example 55 + 20 for the angle + 10 for the element + 3 for the modality.
Zodiac compatibility chart: every pair of signs
This 12 by 12 chart is the same score for every pair of signs, so you can look up a friend or a partner without using the calculator. A pair reads the same in either direction. Aries and Leo is the same number as Leo and Aries.
| Sign | ♈ | ♉ | ♊ | ♋ | ♌ | ♍ | ♎ | ♏ | ♐ | ♑ | ♒ | ♓ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ♈ Aries | 74 | 51 | 88 | 34 | 87 | 50 | 72 | 43 | 88 | 40 | 87 | 46 |
| ♉ Taurus | 51 | 74 | 47 | 87 | 40 | 87 | 45 | 72 | 49 | 87 | 36 | 87 |
| ♊ Gemini | 88 | 47 | 77 | 52 | 87 | 39 | 88 | 49 | 75 | 46 | 87 | 43 |
| ♋ Cancer | 34 | 87 | 52 | 74 | 45 | 88 | 40 | 87 | 44 | 72 | 49 | 88 |
| ♌ Leo | 87 | 40 | 87 | 45 | 74 | 51 | 87 | 34 | 87 | 49 | 72 | 43 |
| ♍ Virgo | 50 | 87 | 39 | 88 | 51 | 77 | 48 | 87 | 43 | 88 | 45 | 75 |
| ♎ Libra | 72 | 45 | 88 | 40 | 87 | 48 | 74 | 51 | 88 | 36 | 87 | 50 |
| ♏ Scorpio | 43 | 72 | 49 | 87 | 34 | 87 | 51 | 74 | 45 | 87 | 40 | 87 |
| ♐ Sagittarius | 88 | 49 | 75 | 44 | 87 | 43 | 88 | 45 | 77 | 52 | 87 | 37 |
| ♑ Capricorn | 40 | 87 | 46 | 72 | 49 | 88 | 36 | 87 | 52 | 74 | 47 | 88 |
| ♒ Aquarius | 87 | 36 | 87 | 49 | 72 | 45 | 87 | 40 | 87 | 47 | 74 | 51 |
| ♓ Pisces | 46 | 87 | 43 | 88 | 43 | 75 | 50 | 87 | 37 | 88 | 51 | 77 |
Zodiac sign compatibility by sign
The 12 short summaries below come straight from the chart above, so they always agree with the calculator.
Aries compatibility
The highest scores for Aries in this chart are Gemini (88%), Sagittarius (88%), Leo (87%). The hardest pairings are Cancer (34%), Capricorn (40%). Two Aries together score 74%. Aries is a cardinal fire sign, so its trine partners are Leo and Sagittarius.
Taurus compatibility
The highest scores for Taurus in this chart are Cancer (87%), Virgo (87%), Capricorn (87%). The hardest pairings are Aquarius (36%), Leo (40%). Two Taurus together score 74%. Taurus is a fixed earth sign, so its trine partners are Virgo and Capricorn.
Gemini compatibility
The highest scores for Gemini in this chart are Aries (88%), Libra (88%), Leo (87%). The hardest pairings are Virgo (39%), Pisces (43%). Two Gemini together score 77%. Gemini is a mutable air sign, so its trine partners are Libra and Aquarius.
Cancer compatibility
The highest scores for Cancer in this chart are Virgo (88%), Pisces (88%), Taurus (87%). The hardest pairings are Aries (34%), Libra (40%). Two Cancer together score 74%. Cancer is a cardinal water sign, so its trine partners are Scorpio and Pisces.
Leo compatibility
The highest scores for Leo in this chart are Aries (87%), Gemini (87%), Libra (87%). The hardest pairings are Scorpio (34%), Taurus (40%). Two Leo together score 74%. Leo is a fixed fire sign, so its trine partners are Sagittarius and Aries.
Virgo compatibility
The highest scores for Virgo in this chart are Cancer (88%), Capricorn (88%), Taurus (87%). The hardest pairings are Gemini (39%), Sagittarius (43%). Two Virgo together score 77%. Virgo is a mutable earth sign, so its trine partners are Capricorn and Taurus.
Libra compatibility
The highest scores for Libra in this chart are Gemini (88%), Sagittarius (88%), Leo (87%). The hardest pairings are Capricorn (36%), Cancer (40%). Two Libra together score 74%. Libra is a cardinal air sign, so its trine partners are Aquarius and Gemini.
Scorpio compatibility
The highest scores for Scorpio in this chart are Cancer (87%), Virgo (87%), Capricorn (87%). The hardest pairings are Leo (34%), Aquarius (40%). Two Scorpio together score 74%. Scorpio is a fixed water sign, so its trine partners are Pisces and Cancer.
Sagittarius compatibility
The highest scores for Sagittarius in this chart are Aries (88%), Libra (88%), Leo (87%). The hardest pairings are Pisces (37%), Virgo (43%). Two Sagittarius together score 77%. Sagittarius is a mutable fire sign, so its trine partners are Aries and Leo.
Capricorn compatibility
The highest scores for Capricorn in this chart are Virgo (88%), Pisces (88%), Taurus (87%). The hardest pairings are Libra (36%), Aries (40%). Two Capricorn together score 74%. Capricorn is a cardinal earth sign, so its trine partners are Taurus and Virgo.
Aquarius compatibility
The highest scores for Aquarius in this chart are Aries (87%), Gemini (87%), Libra (87%). The hardest pairings are Taurus (36%), Scorpio (40%). Two Aquarius together score 74%. Aquarius is a fixed air sign, so its trine partners are Gemini and Libra.
Pisces compatibility
The highest scores for Pisces in this chart are Cancer (88%), Capricorn (88%), Taurus (87%). The hardest pairings are Sagittarius (37%), Leo (43%). Two Pisces together score 77%. Pisces is a mutable water sign, so its trine partners are Cancer and Scorpio.
Zodiac compatibility for marriage
People often search for zodiac compatibility "for marriage", sometimes with a percentage. A high sun-sign score says the signs share an element or an easy angle. It says nothing about money habits, family, goals or how two people handle a disagreement, and those decide most marriages. A lower score means the signs have less in common by temperament, so the relationship may need more deliberate effort. It does not mean the relationship will fail. In Indian astrology, marriage matching uses a different method based on the Moon's position, called Guna Milan, and the Vedic astrology calculator shows how the Moon sign is worked out.
Friendship and work compatibility
The Friendship and Work ratings use the same angle but read it differently. Trines and sextiles come out strong for friends because the signs share an element or support each other. Squares come out challenging for friendship but good for work, because friction between two driven signs can push a project forward. Opposition ranks as good for friendship and mixed for work, since opposite signs balance each other but want different things. These ratings are our reading of the traditional meanings of each angle.
Sun, Moon and rising: compatibility beyond your sun sign
A sun sign comparison is the quickest check, and the least complete. Professional astrologers compare the whole chart, which they call synastry, with the Sun, Moon and rising sign (the Big Three) of both people, plus the planets for love and conflict. That needs a birth time and place for each person. If you want to know how a full chart is built, the birth chart calculator explains each placement. To find the exact sun sign for a birthday on the edge of two signs, use the zodiac sign calculator, which checks the actual year and time.
Chinese zodiac compatibility
The Chinese zodiac has its own compatibility rules, based on three groups of animals four years apart. The Chinese zodiac calculator shows the best matches, the secret friend and the clash for your animal.
Using this calculator in the US, UK, Australia and Canada
Compatibility between signs is the same in all four countries. Searchers in the UK, Australia and Canada often type "star sign compatibility", while US searchers type "zodiac compatibility", and both mean the pairing of two sun signs. If you know the birth dates and not the signs, remember that the UK, Australia and most of Canada write dates day first, so check the order before you choose the month. The month list on this page is by name for that reason.
Does zodiac compatibility work?
There is no scientific evidence that a sun sign pairing predicts how a relationship goes. In a well-known double-blind test published in the journal Nature in 1985, professional astrologers could not match birth charts to personality profiles better than chance. We include the calculator because many people enjoy comparing signs and because the element and angle language is a useful way to talk about temperament. Use the percentage as a conversation starter, not a verdict.
Frequently Asked Questions
Pick the two signs in the calculator. If you enter each person's birth month and day instead, the sign is filled in. The calculator gives a percentage for the pair and shows how it was built from the angle between the signs, their elements and their modalities.
Each pair starts at 55 points and gains or loses points for the angle between the two signs, the element pairing and the modality pairing. The numbers are this page's own scoring rules, shown in full above, not a published astrological standard. The result box shows the breakdown for your pair.
Trine pairs, which are signs of the same element four signs apart (such as Aries with Leo or Sagittarius), score highest. Sextile pairs with compatible elements, such as Aries with Gemini, score as high. The 12 by 12 chart on this page lists the score for every pair.
Square pairs with clashing elements score lowest, for example Aries with Cancer or Leo with Scorpio, which share the lowest score on this page, 34%. A low score means the signs have less in common by temperament. It does not mean they cannot get along.
Yes. This page has a 12 by 12 chart with a percentage for every pair of signs, and a short summary for each sign. The chart is the same one the calculator uses, so a pair reads the same either way round.
It is a comparison of two people's signs for a long-term partnership. This page rates romance, friendship and work separately and gives a single percentage. A sun sign score does not account for values, goals or habits, which matter far more in a marriage, so treat it as one input.
The Friendship rating is based on the angle between the two signs. Trines and sextiles rate strong, because the signs share or support each other's element. Squares rate challenging. The rating appears in the result box next to Romance and Work.
Not on this page. The calculator compares sun signs, which need only a birth date. A comparison using Sun, Moon and rising signs for both people is a different, longer calculation that also needs birth times and places. The birth chart calculator explains how each placement is found.
Yes. It uses sun signs, which only need the date of birth. A birthday on the edge of two signs can be either sign depending on the year and time of birth, which the zodiac sign calculator checks.
Yes. The score is the same whichever sign you put first, because the angle between two signs and the pairing of their elements and modalities do not depend on order.
No scientific evidence says it does, so use the percentage for fun and conversation. See "Does zodiac compatibility work?" above for the test behind that statement.
Yes. It is free, needs no sign-up and asks for no name or email. It runs in your browser, so the dates you enter are not sent anywhere.
Sources & Methodology
There is no standards body for astrology, and no published scoring system for sign compatibility, so the percentage is not a sourced figure. It is this site's own documented formula, built on conventions that Western astrology has used for centuries: the five angles between signs (conjunction, sextile, square, trine and opposition, plus the two minor angles semi-sextile and quincunx), the four elements and the three modalities. The point values in the three scoring tables are our own choices and are shown in full so you can see exactly what the number means. The Romance, Friendship and Work ratings are our reading of the traditional meaning of each angle.
The statement that there is no scientific evidence for astrology's predictions rests on Shawn Carlson's double-blind test, published in Nature 318, 419 to 425 (1985), in which astrologers could not match natal charts to personality profiles better than chance. It did not test sun sign compatibility specifically.