Start with your last period
Use the first day of bleeding from your most recent menstrual period.
Fertility calculator
Estimate your ovulation date, fertile window, and likely next period using your last period date and average cycle length.
Cycle length
22-44 days
Period length
3-10 days
Fertile window
6 days
This tool works best for regular cycles. Estimates are informational only and are not a diagnosis, contraception method, or substitute for medical advice.
Use the first day of bleeding from your most recent period.
Trying to conceive for 12 months, or 6 months if you are 35 or older? A fertility consultation can help you understand the next step.
Guide
Use the first day of bleeding from your most recent menstrual period.
Select how many days your bleeding usually lasts, then choose your average cycle length.
The fertile window includes the five days before ovulation and the day of ovulation.
Likely fertile days, estimated ovulation, and predicted next period dates.
Stress, illness, PCOS, breastfeeding, age, and irregular cycles can change ovulation timing.
Speak with a specialist after 12 months of trying, or 6 months if you are 35 or older.
Common questions
An ovulation calculator estimates ovulation by counting back about 14 days from your expected next period date. The fertile window is usually the five days around ovulation and the ovulation day.
No. Ovulation can vary from cycle to cycle due to stress, illness, irregular periods, PCOS, age, and other health factors. Use the result as an estimate.
Consider a fertility consultation if you have been trying for 12 months, or 6 months if you are 35 or older. Seek care earlier for irregular cycles, known reproductive conditions, or previous fertility concerns.
You can use it as a rough guide, but irregular cycles make ovulation harder to predict. Tracking symptoms and consulting a specialist can give a clearer picture.
Next steps
If you are planning pregnancy, comparing symptoms, or unsure about irregular cycles, explore Pluro centres and fertility resources for personalised care.