Bloom Probability of false positive Probability that BF reports positive set membership for an element that is not in the set \[ {\displaystyle \varepsilon =\left(1-\left[1-{\frac {1}{m}}\right]^{kn}\right)^{k}\approx \left(1-e^{-kn/m}\right)^{k}.} \] \(k\) is the number of hash functions, \(m\) is the number of bits in the array, and \(n\) is the number of entries inserted into the table. Obviously increasing \(m\) and decreasing \(n\) would decrease the \(\varepsilon\) however \(k\) has a optimal point.