Dating Theory Calculator — The 37% Rule
The "37% rule" from optimal stopping theory reveals how many potential partners to date before committing. Enter your estimated lifetime candidate pool and get the mathematically optimal exploration cutoff and your probability of success.
Date and reject this many first — then commit to the next who beats all previous
How does this calculator work?
Based on the secretary problem in optimal stopping theory, date and reject the first n/e ≈ 37% of your expected lifetime partner pool, then commit to the next person who beats everyone seen so far. The maximum probability of landing the very best match under this strategy is ≈ 1/e ≈ 36.8%, the provable mathematical ceiling when candidates arrive in random order and decisions are irrevocable.
Formula
How this is calculated
The secretary problem is a classic mathematical puzzle: you interview n candidates in random order, decide on each one immediately, and cannot go back. The strategy that maximises the probability of selecting the single best candidate is the "look then leap" rule: reject the first r candidates unconditionally (memorising the best seen), then accept the next candidate who beats everyone from the exploration phase.
The calculator finds the exact optimal integer r by computing the success probability for every possible r from 1 to n−1 and choosing the maximum. For large n the optimal r approaches n/e ≈ 0.368 × n (where e ≈ 2.718 is Euler's number), and the maximum probability converges to 1/e ≈ 36.79% — a counter-intuitively achievable ceiling that cannot be improved under the rules.
Applied to dating the "candidates" are serious relationships you expect to have in your lifetime. The model is a deliberate simplification: it assumes random arrival order, perfect recall of who was best, and a single "globally best" outcome. Real relationships involve compatibility, timing, mutual feelings and many other factors that no formula captures. Treat this as a thought experiment about the exploration-vs-commitment trade-off, not as literal relationship advice.
Frequently asked questions
The model assumes candidates arrive in a random order and each must be accepted or rejected on the spot with no recall. Under those constraints, 1/e ≈ 36.8% is provably the maximum achievable probability. Real-life recall, communication and changing preferences all break the model's assumptions and can raise real-world success rates considerably.
In the model a candidate is any person you would seriously consider as a long-term partner. Casual acquaintances or very brief encounters usually do not count. Research suggests most people consider somewhere between 5 and 25 serious relationships in their lifetime; the optimal percentage stays near 37% regardless of the exact number.
The secretary problem is a useful conceptual model, not a dating manual. Its main practical insight is that spending some time exploring before committing is rational — pure exploration (never committing) and pure commitment (marrying the first person you meet) are both suboptimal. The exact 37% threshold should not be applied literally.
Also known as
TG we-Calculate Editorial Team. (2026). Dating Theory Calculator — The 37% Rule [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/dating-theory-calculator
TG we-Calculate Editorial Team. "Dating Theory Calculator — The 37% Rule." TG we-Calculate. 2026. https://we-calculate.com/calculator/dating-theory-calculator.
TG we-Calculate Editorial Team, "Dating Theory Calculator — The 37% Rule," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/dating-theory-calculator
@misc{wecalculate_dating_theory_calculator, title = {Dating Theory Calculator — The 37% Rule}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/dating-theory-calculator}}, year = {2026}, note = {TG we-Calculate} }
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