ToolToUse

Health & Fitness

Pregnancy Due Date Calculator

Estimate a due date from your last period or a known conception date.

An estimate only, not a diagnosis. Assumes a regular 21–45-day cycle in last-period mode; irregular cycles and assisted reproduction need clinical dating. Ultrasound and your clinician may revise the estimate.

Health & Fitness

Pregnancy Due Date Calculator

Local only
Everything stays in your browser

Your text is processed on your device — nothing is uploaded to a server.

How it works

Last-period mode adds 280 days and adjusts by usual cycle length minus 28. Known-conception mode adds 266 days and ignores the cycle setting. Calendar calculations use whole dates without timezone shifts. An estimate only, not a diagnosis. Assumes a regular 21–45-day cycle in last-period mode; irregular cycles and assisted reproduction need clinical dating. Ultrasound and your clinician may revise the estimate.

Good to know

Frequently asked questions

How do I use it?

Fill in the options and press “Calculate”. Check the result, then copy or download it.

How does it work?

Last-period mode adds 280 days and adjusts by usual cycle length minus 28. Known-conception mode adds 266 days and ignores the cycle setting. Calendar calculations use whole dates without timezone shifts.

Are there limitations?

An estimate only, not a diagnosis. Assumes a regular 21–45-day cycle in last-period mode; irregular cycles and assisted reproduction need clinical dating. Ultrasound and your clinician may revise the estimate.

Is my data uploaded?

No. Everything is processed in your browser and nothing is sent to a server. No account is needed.

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