HerSensi tool
Period Date Estimator
Estimate a planning date from your last period and usual cycle length — without pretending a cycle is perfectly predictable.
Period date estimator
Your result
Your answer will appear here
Nothing is prefilled. Add only the information you are comfortable using in this browser.
This is a planning estimate, not a prediction of whether your cycle is medically normal.
Worked example
What this looks like in real life
If your last period started 1 August and your cycles are usually around 30 days, the tool adds 30 days to give an approximate next start date.
If your cycles vary from 27 to 34 days, one exact date is false precision. Use your own range and the Cycle Variation tool too.
What the tool cannot tell you
Does not diagnose irregular periods.
Does not confirm or rule out pregnancy.
Hormonal contraception, postpartum changes and perimenopause can make simple estimates less useful.
Continue from the result