The reciprocal of the average of the reciprocals.
Say we have "n" values {a,b,c,...}, then we can calculate:
Harmonic Mean = n / (1/a + 1/b + 1/c + ...)
Steps:
• Calculate the reciprocal (1/value) for every value.
• Find the average of those reciprocals (add them and divide by n)
• Then do the reciprocal of that average (=1/average)
See: Reciprocal