WhenMyBaby - OPK Calculator

Ovulation Predictor Kit Test Days Calculator	How OPKs Work
Create your ovulation prediction kit (OPK) test schedule for your current cycle, including a chart to track your ovulation test results! Enter info about your cycle, and the start cycle day to test per the instructions for the OPK you've purchased. Or, click your cycle length from the chart below which matches your OPK's instructions.

Today's Date (Fri Jul 4, 2008)

Period start date:

Average cycle length:

How to calculate cycle length

Start OPK testing on Cycle Day?

Check your OPK instructions

Number of Ovulation Test Days?

The number of tests provided with your OPK

Doesn't match your OPK Instructions? Get Next chart...
Average Cycle Length	Start Testing on Cycle Day #
21	5
22	5
23	6
24	7
25	8
26	9
27	10
28	11
29	12
30	13
31	14
32	15
33	16
34	17
35	18
36	19
37	20
38	21
39	22
40	23

Haven't purchased your Ovulation Predictor Kit (OPK) yet?

You can what-if calcuate to check approximately when to ovulation test in your current cycle, or if it's already too late.

Once you buy your ovulation tests, re-calculate to get your revised schedule.