Conception Calculator
Estimate your conception date from your last period.
Result
Results are estimates for general information only and are not professional advice.
Estimating conception
Conception usually occurs around ovulation, roughly two weeks before the next period. From your last period and cycle length, this calculator estimates the likely conception date and the matching due date.
Frequently Asked Questions
What is the Conception Calculator?
Estimate your conception date from your last period. It runs instantly in your browser and is completely free to use.
What do I need to enter to use the Conception Calculator?
The Conception Calculator asks for the following values (2): First day of last period, Cycle length (days). Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the Conception Calculator?
The Conception Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the Conception Calculator free, and do I need an account?
Yes. The Conception Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.