When are you most likely to conceive?
Getting pregnant depends on timing. The chance is highest in the two to three days before ovulation and on ovulation day itself, and drops to almost zero the day after.
This calculator finds your best days from your last period and cycle length, tells you when to take a pregnancy test and gives the due date if you conceive this cycle.
How it is calculated
Ovulation = last period + (cycle length − 14 days)
Best days = 2 days before ovulation through ovulation day
A large study of couples measured the chance of conceiving on each day around ovulation. The calculator shows those figures.
Worked example
Last period 1 January, 28-day cycle
- Ovulation
- Thu, 15 Jan 2026
- Best days
- 13 Jan – 15 Jan 2026
- Take a test from
- Thu, 29 Jan 2026
- Due date if conceived
- Thu, 8 Oct 2026
Tips for getting pregnant
- Intercourse every 1–2 days in the fertile window works well.
- Start folic acid (400 mcg) before conceiving.
- Maintain a healthy weight, avoid tobacco and limit alcohol and caffeine.
- See a doctor after 12 months of trying (6 months if the woman is over 35).