Coin Flip Streak Probability
Calculator

Inputs

Expected streak occurrences
0.5

Results

Expected streak occurrences
0.5
Streak probability (%)
39.346934
Single-attempt streak probability (%)
3.125

Gaming results

Expected streak occurrences0.5
Streak probability (%)39.346934
Single-attempt streak probability (%)3.125

formula-map diagram

Expected streak occurrences
0.5
Streak probability (%)
39.346934
Single-attempt streak probability (%)
3.125

Game math relationship

Formula

E ≈ (n − k + 1)×p^k ; P(≥1 streak) ≈ 1 − e^(−E) (Poisson approx.)

= 0.5

Note

This is a simplified model: it applies the standard probability or game-math formula to the numbers you entered. Real games add pity systems, drop-rate tiers, rounding, server-side variance and balance patches, so treat the result as an estimate rather than a guarantee.

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