Birthday Compatibility Calculator
Check your zodiac compatibility by date of birth. Enter two birthdays to find both signs and your score out of 100, with the strengths and challenges for your pair.
By the 4Lovebirds team · Updated November 7, 2026
What Is Birthday Compatibility?
Birthday compatibility compares two people by their dates of birth. Calculators use one of three methods: zodiac sun signs, numerology life path numbers, or synastry, which compares two full birth charts and needs birth times. This calculator uses sun signs. Each birth date gives a sign, and the two signs get a set score from our chart of all 78 sign pairings.
How Birthday Compatibility Works
Your birth date determines your zodiac sign, which plays a crucial role in astrological compatibility. Each zodiac sign has unique traits, strengths, and challenges that influence relationship dynamics:
- Birth dates reveal your sun sign and core personality traits
- Zodiac elements (Fire, Earth, Air, Water) affect compatibility
- Only the month and day matter. The birth year is not used
- If you were born within a day of a sign change, check both signs
Example: born March 30 and August 5? That makes Aries and Leo, two fire signs, with a score of 85.
Why Use Our Birthday Compatibility Calculator?
Features
- Instant zodiac sign identification
- A love score out of 100 for your two signs
- Strengths and challenges for your pair
- A share card you can send to your partner
Benefits
- Understand relationship dynamics
- Identify potential challenges
- Discover relationship strengths
- Get something new to talk about together
Understanding Zodiac Date Ranges
Fire Signs
- Aries (Mar 21 - Apr 19)
- Leo (Jul 23 - Aug 22)
- Sagittarius (Nov 22 - Dec 21)
Earth Signs
- Taurus (Apr 20 - May 20)
- Virgo (Aug 23 - Sep 22)
- Capricorn (Dec 22 - Jan 19)
Air Signs
- Gemini (May 21 - Jun 20)
- Libra (Sep 23 - Oct 22)
- Aquarius (Jan 20 - Feb 18)
Water Signs
- Cancer (Jun 21 - Jul 22)
- Scorpio (Oct 23 - Nov 21)
- Pisces (Feb 19 - Mar 20)
Birthday compatibility chart
Every sign pair on one chart. Find your sign in the first column and their sign along the top. Each score links to that pair's full reading.
Scores run from 50 to 91, and the average is 73. Pairs within one element score highest, and air paired with water or earth scores lowest.
| Your sign ↓ · Their sign → | ♈︎Ari | ♉︎Tau | ♊︎Gem | ♋︎Can | ♌︎Leo | ♍︎Vir | ♎︎Lib | ♏︎Sco | ♐︎Sag | ♑︎Cap | ♒︎Aqu | ♓︎Pis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aries | 75 | 60 | 80 | 60 | 85 | 60 | 71 | 70 | 85 | 55 | 85 | 60 |
| Taurus | 60 | 80 | 55 | 80 | 60 | 85 | 70 | 75 | 55 | 91 | 55 | 87 |
| Gemini | 80 | 55 | 86 | 55 | 87 | 55 | 90 | 60 | 90 | 55 | 90 | 60 |
| Cancer | 60 | 80 | 55 | 90 | 50 | 85 | 60 | 90 | 55 | 80 | 50 | 90 |
| Leo | 85 | 60 | 87 | 50 | 90 | 64 | 91 | 70 | 90 | 60 | 80 | 55 |
| Virgo | 60 | 85 | 55 | 85 | 64 | 85 | 70 | 77 | 60 | 85 | 65 | 80 |
| Libra | 71 | 70 | 90 | 60 | 91 | 70 | 85 | 65 | 80 | 55 | 90 | 60 |
| Scorpio | 70 | 75 | 60 | 90 | 70 | 77 | 65 | 90 | 64 | 80 | 55 | 90 |
| Sagittarius | 85 | 55 | 90 | 55 | 90 | 60 | 80 | 64 | 80 | 60 | 85 | 60 |
| Capricorn | 55 | 91 | 55 | 80 | 60 | 85 | 55 | 80 | 60 | 85 | 50 | 85 |
| Aquarius | 85 | 55 | 90 | 50 | 80 | 65 | 90 | 55 | 85 | 50 | 90 | 60 |
| Pisces | 60 | 87 | 60 | 90 | 55 | 80 | 60 | 90 | 60 | 85 | 60 | 90 |
Scores are out of 100 and come from each pair's elements and traits.
Frequently Asked Questions
How accurate is birthday compatibility?
It's astrology, which is not a science. The calculator turns each birth date into a sun sign and shows the set score for that pair. Enjoy it, but don't base big decisions on it.
What makes certain birthdays compatible?
In sun-sign astrology, signs of the same element, fire with air, and earth with water are seen as easier matches. Our score uses only the sun sign from each birth date.
Can birthdays predict relationship success?
While birthdays and zodiac compatibility provide helpful insights, successful relationships depend on many factors including communication, mutual respect, and effort from both partners.
What if I was born on a cusp?
The sun changes signs on slightly different days each year, usually between the 19th and the 23rd. This calculator uses fixed date ranges, such as Aries from March 21 to April 19. If your birthday is within a day of a boundary, check both signs.
Does the birth year matter?
Not for this calculator. Your sun sign comes from the month and day, so the year doesn't change your score. Numerology calculators use the full date, year included.
Which zodiac signs are most compatible?
On our chart, Taurus and Capricorn, and Leo and Libra, score highest at 91. Thirteen pairs follow at 90, including Gemini and Libra, Cancer and Scorpio, and Scorpio and Pisces.
Which zodiac signs are least compatible?
Cancer and Leo, Cancer and Aquarius, and Capricorn and Aquarius score lowest at 50. A low score means your styles differ. It doesn't mean the relationship can't work.
Are two people with the same sign compatible?
Mostly yes. Same-sign pairs average 85.5 on our chart, from 75 for two Aries to 90 for two Cancers, Leos, Scorpios, Aquarians or Pisces.