A zodiac compatibility calculator that explains the percentage
This free zodiac compatibility calculator compares two star signs the way sun-sign astrology books do: by element (fire, earth, air, water), modality (cardinal, fixed, mutable) and the aspect the two signs make around the zodiac wheel. Pick two Sun signs for a quick answer, or add Moon and Rising signs to compare the full “Big Three”.
You get a percentage, but unlike most compatibility sites this one tells you exactly how it is made: each pairing of signs gets points for its aspect on a published scale, and the percentage is the average. Astrology compatibility is folklore, not science, so use it for tradition and entertainment, not prediction or advice.
How to use the Zodiac Compatibility Calculator
- Choose Person A’s Sun sign and, if you know them, the Moon and Rising signs.
- Do the same for Person B.
- Read the harmony score and the aspect between the two Sun signs, shown on the wheel.
- Check the table for every pairing used, with its element, modality and points.
- Open How the points are given to see the scale, then use Copy result.
Zodiac Compatibility Calculator features
Sun, Moon and Rising
Up to five pairings: Sun–Sun, Moon–Moon, Rising–Rising and each person’s Sun with the other’s Moon.
Element and modality
Every pairing says whether the elements match, complement or clash, and whether the modalities are shared.
Aspects on a wheel
The two Sun signs are marked on a zodiac wheel, with the aspect named in the centre.
Open scoring
The points for each aspect are listed in full, and the arithmetic is printed under the table.
Links to other systems
Vedic kundli matching and the Chinese zodiac are a click away.
Elements, modalities and aspects
The twelve signs fall into four elements — fire (Aries, Leo, Sagittarius), earth (Taurus, Virgo, Capricorn), air (Gemini, Libra, Aquarius) and water (Cancer, Scorpio, Pisces) — and three modalities — cardinal (Aries, Cancer, Libra, Capricorn), fixed (Taurus, Leo, Scorpio, Aquarius) and mutable (Gemini, Virgo, Sagittarius, Pisces). Fire and air are traditionally called complementary, as are earth and water.
Counting how many signs apart two signs are gives the aspect, and the aspect decides both relationships at once: signs four apart (a trine) share an element; two apart (a sextile) have complementary elements; three apart (a square) share a modality but not a compatible element; six apart (an opposition) share a modality with complementary elements; one or five apart (semi-sextile, quincunx) share neither.
How the percentage is worked out
Each pairing scores out of 10 by its aspect: trine 9, sextile 8, same sign 7, opposition 6, semi-sextile 4, square 3, quincunx 2. The order follows the usual ranking in sun-sign astrology; the exact numbers are this page’s choice for turning that order into a score. With Moon and Rising signs entered, every pairing counts equally and the score is their average × 10.
Worked example: Leo and Sagittarius are four signs apart, a trine of two fire signs: 9 points, 90%. Add Leo’s Moon in Cancer and Rising in Libra, and Sagittarius’s Moon in Pisces and Rising in Aquarius: the Moons and the Rising signs are also trines (9 each), but Leo–Pisces and Cancer–Sagittarius are quincunxes (2 each), so the score is (9 + 9 + 9 + 2 + 2) ÷ 5 = 6.2 → 62%.
Zodiac compatibility for marriage
Sun signs are a very small part of a birth chart. Western astrologers comparing two people for a serious relationship look at full charts — the synastry calculator does that. In India, marriage matching normally uses Vedic kundli matching (Ashtakoota guna milan) from the Moon’s nakshatra, which works quite differently. For a number-based comparison there is the numerology compatibility calculator.
Zodiac Compatibility Calculator FAQ
How is the zodiac compatibility percentage calculated?
Each pair of signs scores points for its aspect (trine 9 down to quincunx 2); this zodiac compatibility calculator averages the pairings and multiplies by 10. The scale is shown on the page.
Can I compare Sun, Moon and Rising signs?
Yes. Add Moon and Rising signs for either or both people; the score then includes up to five pairings.
Which zodiac signs are most compatible?
In sun-sign astrology, signs of the same element (trines) and of complementary elements (sextiles) are usually ranked highest, and squares and quincunxes lowest.
Is zodiac compatibility accurate?
No study has found that star signs predict relationship success. It is folklore for tradition and entertainment, not prediction or advice.
Is this the same as kundli matching?
No. Kundli matching is the Vedic method based on the Moon’s nakshatra in the sidereal zodiac. This page uses Western tropical signs.
What about Chinese zodiac compatibility?
Chinese astrology uses animal years, not star signs. Use the Chinese zodiac calculator to find each animal.