How the Compatibility Score Is Calculated
MBTI compatibility is not a clinical instrument — it is a game built from rules over four letter axes. What matters is not the number but why the number came out that way, so this tool publishes its formula openly. Every pair starts at 50 points, each axis adds or subtracts, and results land between 35 and 99.
The axes are weighted differently. E/I adds +8 when the letters differ (complementary energy) and +4 when they match (an easy shared rhythm). S/N carries the most weight here: +14 when they match, −6 when they do not, because someone trading concrete facts and someone trading meanings can say the same words and still miss each other. T/F gives +10 when different (a balance of judgment and empathy) and +5 when the same. J/P is nearly neutral at +8 versus +6. On top of that, pairings commonly named soulmates in NF/NT lore add +14, and identical types add +2.
Knowing the weights tells you how to read the result. A score above 90 usually means the S/N letters match and the soulmate bonus applied; a score in the 60s usually means S/N differs. So a low score is less "you do not fit" and more "your conversations run on different layers, so you will each need to explain a little more." The commentary on the result screen is written from that angle.
One honest caveat. Personality type predicts far less about real relationship satisfaction than people assume. Research consistently finds that how couples handle conflict, how often they express appreciation, and whether they treat each other with respect explain much more than any type pairing. Use this score as a conversation starter and let the two of you write the conclusion.