Dates are estimates
Pregnancy calculators use common dating rules. Ultrasound, cycle history, or IVF details may change your official date.
Ovulation calculator
Estimate your fertile window.
Enter your last period date and average cycle length to estimate ovulation, fertile window, and next period date.
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One small answer at a time
Use the result as a planning note, then confirm important details with your care team.
Live toolUpdates instantly
Estimated ovulation dateMay 21, 2026
Fertile window startsMay 16, 2026
Fertile window endsMay 21, 2026
Next periodJune 4, 2026
Helpful context
Simple answers before you use the result.
Use it as a planning guide
Your result can help with appointments, checklists, baby names, registry timing, and weekly planning.
Ask when unsure
If a date or symptom feels confusing, your clinician is the best place to confirm what it means for you.
Sources and safety
BumpCalc uses common pregnancy dating rules for planning. For official dating, ultrasound timing, IVF details, symptoms, or urgent concerns, use your clinician's guidance.