By the Age-Finder team · Last updated 7 November 2026
Quick answer
Give the calculator two dates of birth and it names both star signs and scores the pair from the angle between them. A trine, four signs apart, scores 95%, the highest; a square, three apart, scores 45%, the lowest. The score is for fun, not a prediction.
The Zodiac Compatibility calculator finds two people’s Western star signs from their dates of birth and shows how the signs traditionally get along, using their elements and the angle between them on the zodiac wheel. The score is for fun, not a prediction.
How to Use the Zodiac Compatibility Calculator
Enter the first person’s date of birth. Enter the second person’s date of birth. Select Calculate. The result shows both signs, their elements, the relationship between them and a match score.
The calculator adds a note of its own: astrology is for fun and reflection, not prediction, and any two people can build a good relationship. To look up one sign with its traits, use the Zodiac Sign Finder. For the Chinese zodiac version, use Chinese Zodiac Compatibility.
Zodiac Sign Dates
The calculator uses the same dates as our Zodiac Sign Finder. Sign boundaries can shift by a day in some years, so if you were born on the first or last day of a sign, check your exact sign with a birth chart.
| Sign | Dates | Element |
|---|---|---|
| Aries | 21 March to 19 April | Fire |
| Taurus | 20 April to 20 May | Earth |
| Gemini | 21 May to 20 June | Air |
| Cancer | 21 June to 22 July | Water |
| Leo | 23 July to 22 August | Fire |
| Virgo | 23 August to 22 September | Earth |
| Libra | 23 September to 22 October | Air |
| Scorpio | 23 October to 21 November | Water |
| Sagittarius | 22 November to 21 December | Fire |
| Capricorn | 22 December to 19 January | Earth |
| Aquarius | 20 January to 18 February | Air |
| Pisces | 19 February to 20 March | Water |
How Compatibility Is Worked Out
Astrology traditionally judges two signs by how far apart they are on the zodiac wheel. The calculator names the relationship and gives a score:
| Signs apart | Name | Traditional view | Score |
|---|---|---|---|
| 0 | Same sign | Similar, comfortable, sometimes too alike | 80% |
| 1 | Neighbours | Different temperaments side by side | 55% |
| 2 | Sextile | Friendly and easy-going | 85% |
| 3 | Square | Tension and challenge | 45% |
| 4 | Trine | The most harmonious | 95% |
| 5 | Quincunx | Awkward, needs adjustment | 50% |
| 6 | Opposites | Attraction with contrast | 70% |
Elements
Each sign belongs to one of four elements. Signs of the same element share a trine, and Fire is traditionally paired with Air, and Earth with Water. Taurus and Virgo (both Earth) are a trine; Taurus and Leo (Earth and Fire) are a square.
When the two elements traditionally work well together, the calculator says so in the result; when they are a less natural mix, it says the pair can be complementary rather than similar.
The Best and Hardest Match for Every Sign
Because the score depends only on the angle between the two signs, every sign has the same pattern: two trines score 95%, two sextiles score 85%, and two squares score 45%. The table below lists them for all twelve signs, taken straight from the calculator.
| Sign | Best matches, trine 95% | Also strong, sextile 85% | Hardest, square 45% |
|---|---|---|---|
| Aries | Leo, Sagittarius | Gemini, Aquarius | Cancer, Capricorn |
| Taurus | Virgo, Capricorn | Cancer, Pisces | Leo, Aquarius |
| Gemini | Libra, Aquarius | Aries, Leo | Virgo, Pisces |
| Cancer | Scorpio, Pisces | Taurus, Virgo | Aries, Libra |
| Leo | Aries, Sagittarius | Gemini, Libra | Taurus, Scorpio |
| Virgo | Taurus, Capricorn | Cancer, Scorpio | Gemini, Sagittarius |
| Libra | Gemini, Aquarius | Leo, Sagittarius | Cancer, Capricorn |
| Scorpio | Cancer, Pisces | Virgo, Capricorn | Leo, Aquarius |
| Sagittarius | Aries, Leo | Libra, Aquarius | Virgo, Pisces |
| Capricorn | Taurus, Virgo | Scorpio, Pisces | Aries, Libra |
| Aquarius | Gemini, Libra | Aries, Sagittarius | Taurus, Scorpio |
| Pisces | Cancer, Scorpio | Taurus, Capricorn | Gemini, Sagittarius |
Two things stand out. First, the best match for every sign is always a sign of the same element: Aries pairs with Leo and Sagittarius, both Fire; Taurus pairs with Virgo and Capricorn, both Earth.
Second, the hardest match is never a sign of the same element: the square is always a different element and a different mode, so the two signs share nothing in the system.
Worked Example
Someone born on 14 May 1990 is a Taurus, an Earth sign. Someone born on 10 August 1992 is a Leo, a Fire sign.
Taurus and Leo are three signs apart, a square, so the traditional reading is a pair with friction, scoring 45%: steady Taurus and expressive Leo can balance each other, but only with effort.
The Full 12 by 12 Chart
Find your sign in the first column, then your partner’s sign along the top. Every square is the score the calculator gives that pair, from the same formula, so the chart and the calculator always agree. Read it as a guide to a starting point, not a verdict.
| Aries | Taurus | Gemini | Cancer | Leo | Virgo | Libra | Scorpio | Sagittarius | Capricorn | Aquarius | Pisces | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aries | 80% | 55% | 85% | 45% | 95% | 50% | 70% | 50% | 95% | 45% | 85% | 55% |
| Taurus | 55% | 80% | 55% | 85% | 45% | 95% | 50% | 70% | 50% | 95% | 45% | 85% |
| Gemini | 85% | 55% | 80% | 55% | 85% | 45% | 95% | 50% | 70% | 50% | 95% | 45% |
| Cancer | 45% | 85% | 55% | 80% | 55% | 85% | 45% | 95% | 50% | 70% | 50% | 95% |
| Leo | 95% | 45% | 85% | 55% | 80% | 55% | 85% | 45% | 95% | 50% | 70% | 50% |
| Virgo | 50% | 95% | 45% | 85% | 55% | 80% | 55% | 85% | 45% | 95% | 50% | 70% |
| Libra | 70% | 50% | 95% | 45% | 85% | 55% | 80% | 55% | 85% | 45% | 95% | 50% |
| Scorpio | 50% | 70% | 50% | 95% | 45% | 85% | 55% | 80% | 55% | 85% | 45% | 95% |
| Sagittarius | 95% | 50% | 70% | 50% | 95% | 45% | 85% | 55% | 80% | 55% | 85% | 45% |
| Capricorn | 45% | 95% | 50% | 70% | 50% | 95% | 45% | 85% | 55% | 80% | 55% | 85% |
| Aquarius | 85% | 45% | 95% | 50% | 70% | 50% | 95% | 45% | 85% | 55% | 80% | 55% |
| Pisces | 55% | 85% | 45% | 95% | 50% | 70% | 50% | 95% | 45% | 85% | 55% | 80% |
Counting the 78 different pairings: 12 trines score 95%, 12 sextiles score 85%, 12 same-sign pairings score 80%, 6 oppositions score 70%, 12 neighbour pairings score 55%, 12 quincunxes score 50%, and 12 squares score 45%.
The 24 highest-scoring pairings are all same-sign pairs or same-element trines, and the squares and quincunxes fill the bottom 24 places.
How the Same Score Reads in Love, Friendship and Work
The calculator gives one score for a pair, and the same number reads differently depending on the relationship. Other calculators split the score into themes, but this one does not, so the guide below is a traditional reading of each aspect across the three, not a second set of scores.
- Trine (95%). In love, easy and natural; in friendship, a comfortable rhythm with little friction; at work, a smooth partnership where the two agree quickly. The risk is coasting: nothing pushes either person to grow.
- Sextile (85%). In love, friendly and easy-going, with room to grow; in friendship, one of the best starting points for a lasting friendship; at work, a good pairing for collaboration, with different skills that fit together.
- Same sign (80%). In love, deeply comfortable, because the two want the same things; in friendship, instant understanding; at work, a shared approach that can turn into a blind spot if nobody challenges the plan.
- Opposites (70%). In love, attraction through contrast, with each person offering what the other lacks; in friendship, an interesting difference that keeps things fresh; at work, a complementary pair, where one starts and the other finishes.
- Neighbours (55%). In love, two different temperaments living side by side, with little in common to build on; in friendship, a pairing that needs shared interests outside the signs; at work, a pairing that needs clear roles to avoid talking past each other.
- Quincunx (50%). In love, awkward at first, needing constant adjustment; in friendship, a pairing that takes effort to understand; at work, a pairing where the two have to translate for each other.
- Square (45%). In love, the most challenging pairing, with friction that needs work; in friendship, a lively pairing that can push both people; at work, productive tension, where the disagreement is the point.
Why Compatibility Scores Differ Between Sites
There is no single standard. Some sites use only elements, some use the angle between signs, and others include the Moon and rising signs from a full birth chart. This calculator uses the classic sign-to-sign angles and elements, the basis of most traditional readings.
Treat any score as a talking point, not a verdict. A study that scored 60,000 generated chart pairs found that the two Sun signs explained only 22.7% of a full-chart compatibility score, so even a complete chart leaves most of the result to the rest of the birth chart.
What Matters More Than Signs
Research has not found that star signs predict relationship success. Shared values, communication and kindness make relationships work. Enjoy the result as a fun way to talk about personalities. A 1985 test in Nature asked astrologers to match birth charts to personality profiles and found they did no better than chance (Carlson, 1985).
Modes: Cardinal, Fixed and Mutable
Astrology also groups the signs into three modes, which describe how each sign acts: Cardinal signs (Aries, Cancer, Libra, Capricorn) start things and take the lead. Fixed signs (Taurus, Leo, Scorpio, Aquarius) keep things steady and resist change.
Mutable signs (Gemini, Virgo, Sagittarius, Pisces) adapt and move between ideas. Signs of the same mode are always three or six signs apart, a square or an opposition, which is why those pairings are described as strong-willed: both people tend to act in the same way.
Element Pairs at a Glance
| Pair | Traditional reading |
|---|---|
| Fire and Fire, Fire and Air | Energetic, inspiring, quick to act |
| Earth and Earth, Earth and Water | Steady, supportive, practical |
| Fire and Earth | Drive meets caution: can balance or clash |
| Fire and Water | Passion meets feeling: intense |
| Air and Earth | Ideas meet practicality |
| Air and Water | Thinking meets feeling |
Compatibility Beyond Romance
The same sign relationships are used to talk about friendships, family members and colleagues, not only couples. A trine between two friends suggests an easy rhythm, while a square between colleagues can explain why meetings feel lively.
Because the result depends only on the two signs, everyone born in the same sign pair gets the same reading, so use it for fun and conversation.
What other zodiac compatibility calculators offer
Most zodiac compatibility calculators on the first page give the same two signs this one does. What sets them apart is how they score the pair and what else they show. The comparison below is against the three zodiac compatibility calculators that rank highest.
| Feature | Age-Finder | LoveCalcs | AstroSight | LoveVerse |
|---|---|---|---|---|
| Both signs from birth dates | Yes | Yes | Yes | Yes |
| Match score | Yes, one score | Yes, five factors | Yes, per theme | Yes, per theme |
| 12 by 12 chart | No, in the guide | Yes | Yes | Not shown |
| Per-theme scores | No, in the guide | Not shown | Yes, love, friendship, communication, sexual | Yes, romance, trust, communication, passion, long-term |
| Moon or rising signs | No | No | Yes, Vedic Guna Milan | Yes, simplified estimate with birth time |
| Ruling planets | No | Yes | Not shown | Not shown |
| Best and hardest per sign | Yes, in the guide | Yes | Yes | Yes |
| Free to use, no account needed | Yes | Yes | Yes | Yes |
The shortfalls in the tool: it gives one score for the pair, with no split by theme; it has no 12 by 12 chart built in; and it uses sun signs only, with no Moon sign, no rising sign and no ruling planets.
What it adds is the chart and the per-theme reading worked through by hand in the guide, and a score formula that is simple enough to check: the score is the angle between the two signs, nothing else.
Frequently Asked Questions
Which zodiac signs are most compatible?
Traditionally, signs four apart (a trine) are the most harmonious: signs of the same element, such as Aries, Leo and Sagittarius.
Which signs are least compatible?
Signs three apart (a square), such as Taurus and Leo, are traditionally the most challenging pairing.
Are opposite signs compatible?
Opposite signs, six apart, are said to attract each other through contrast. The calculator scores them in the middle.
What if I was born on a cusp?
If your birthday is on the first or last day of a sign, check your exact sign with a birth chart for your year, because the boundary can move by a day.
Is zodiac compatibility real?
There is no scientific evidence that star signs affect compatibility. The calculator is for fun and conversation.
What does my match score mean?
The score reflects the traditional view of the angle between the two signs: 95% for a trine, the most harmonious pairing, down to 45% for a square, the most challenging. It is a fun summary, not a measure of a real relationship.
Does the year of birth matter?
Not for sun signs: they depend only on the day and month. The year matters for the Chinese zodiac, which you can compare with our Chinese Zodiac Compatibility calculator.
Why is my partner’s sign different from what I expected?
Sign dates are the same every year in this calculator, but a birthday on the edge of a sign can fall in the neighbouring sign in some years. Check the dates table above, or use a full birth chart for an exact answer.
Can the same two signs get different scores?
No. The score depends only on the two signs, so every pair with the same two signs gets the same score. Two people with the same sign pair can still have very different relationships, because the score is a starting point, not a measure of the people.
Sources
- Traditional Western astrology aspects: conjunction, sextile, square, trine, quincunx and opposition (the seven aspects this calculator scores).
- Carlson, S. (1985). A double-blind test of astrology. Nature 318, 419-425 (astrologers matched birth charts to personality profiles no better than chance).
- Natal Junction, Best and Worst Match for Every Zodiac Sign, Ranked (the 60,000-chart-pair study: the two Sun signs explained only 22.7% of a full-chart score).
- Age-Finder Zodiac Sign Finder (the sign dates used here).
- Age-Finder methodology (how ages and 29 February birthdays are calculated).