The formula to calculate the average menstrual cycle length is:
\[ \text{Average Cycle Length} = \frac{\text{Sum of Cycle Lengths}}{\text{Number of Cycles}} \]
Where:
The average menstrual cycle length is the average number of days between the start of one period and the start of the next, calculated by dividing the sum of cycle lengths by the number of cycles.
Consider an example where the cycle lengths are:
Using the formula to calculate the average cycle length:
\[ \text{Average Cycle Length} = \frac{28 + 30 + 27 + 29 + 31}{5} = 29 \]
This means that the average menstrual cycle length for this example is 29 days.