How to Calculate Binomial Probability with BINOM.DIST in Excel

Use BINOM.DIST to find the chance of exactly, at most or at least a number of successes — like sales from cold calls.

You will learn to

• Find the probability of exactly k successes
• Find the probability of at most k successes
• Find the probability of at least k successes

How it works

BINOM.DIST answers "how likely is it to get k successes out of n tries?" when every try has the same chance of success and the tries are independent — calls that convert, parts that pass inspection, emails that get opened.

Set cumulative to FALSE for exactly k and TRUE for k or fewer. For "at least k" use 1 minus the cumulative probability of k−1: =1-BINOM.DIST(k-1,n,p,TRUE). Off-by-one mistakes are the most common error, so say the question out loud before you type.

=BINOM.DIST(3,20,0.15,FALSE)