Sites like AstroSage, Love-Meter and ChineseFortuneCalendar feature calculators that measure love compatibility between two people based on their birth dates. Love-Meter also requires the user to enter the names of the two people.
AstroSage and Love-Meter compatibility calculations are based on numerology, the pseudoscience that deals with the meanings behind numbers. The AstroSage calculator results are expressed in percentage (0-100), while Love-Meter calculator results feature four possibilities: very compatible, compatible, neutral or not compatible.
The ChineseFortuneCalendar love compatibility calculator is based on the Chinese horoscope and displays the results ranging from -10 (calling it the "Meet at Court" rank) to +10 (the "Romeo and Juliet Love Story" rank).