Enter Your Cycle Details
First Day of Your Last Menstrual Period:
Average Length of Your Menstrual Cycle:
Select your cycle length
I don’t know
21 days
22 days
23 days
24 days
25 days
26 days
27 days
28 days (average)
29 days
30 days
31 days
32 days
33 days
34 days
35 days
Luteal Phase Length (optional):
Leave blank if unsure
10 days
11 days
12 days
13 days
14 days
15 days
16 days
17 days
Typically 12–14 days. Leave blank if unsure.
Calculate Ovulation Date