01
Cycle planning
Ovulation & fertile-window estimator
Estimate potentially fertile days from a regular cycle.
Open the tool →Small tools. More understanding.
A little clarity for
your next step.
Understand your cycle, estimate key dates or prepare for a semen test. Free tools with plain-English results and a clear explanation of what they can—and cannot—tell you.
No account needed. Your entries are calculated in the page, not submitted to ProFertility or saved to your patient record by these tools. Calendar estimates cannot confirm ovulation or tell you your individual chance of pregnancy.
02
Understand your pattern
Menstrual cycle-length calculator
Turn period start dates into cycle lengths and a simple summary.
Open the tool →03
Early pregnancy planning
Pregnancy due-date estimator
Estimate a due date from your last period and usual cycle length.
Open the tool →04
Prepare for a test
Semen-sample abstinence planner
Check the interval between last ejaculation and a planned sample.
Open the tool →Built to be useful. Clear about the limits.
Each tool includes its calculation method, linked sources and situations in which it should not be used. Educational content prepared by ProFertility, updated 23 October 2026. No tool diagnoses a condition or replaces personalised care.