LMP from Due Date Calculator
Reconstruct the LMP your provider's dating implies — useful for forms, apps and cross-checking records.
When a dating scan adjusted your EDD, the 'implied LMP' it represents may differ from your remembered period date — that's the scan correcting ovulation-timing assumptions, not an error. Apps that only accept LMP input need this implied date, not the remembered one, to track in sync with your clinic.
Formula
For general information only. Pregnancy and infant care decisions must be guided by your treating clinician or midwife — always defer to their assessment.
Reconstruct the LMP your provider's dating implies — useful for forms, apps and cross-checking records. The LMP from Due Date Calculator is a free, private lmp from due date tool — every result computes instantly in your browser with no sign-up and no data upload.
About LMP from Due Date Calculator
When a dating scan adjusted your EDD, the 'implied LMP' it represents may differ from your remembered period date — that's the scan correcting ovulation-timing assumptions, not an error. It applies LMP = EDD − 280 days; conception ≈ EDD − 266 days. Use the LMP from Due Date Calculator to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use LMP from Due Date Calculator
- 1Enter your details in the LMP from Due Date Calculator input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use LMP from Due Date Calculator?
- ✓Instant lmp from due date result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (ACOG CO 700)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the LMP from Due Date Calculator work?+
When a dating scan adjusted your EDD, the 'implied LMP' it represents may differ from your remembered period date — that's the scan correcting ovulation-timing assumptions, not an error. The calculation uses the formula: LMP = EDD − 280 days; conception ≈ EDD − 266 days. Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the LMP from Due Date Calculator accurate, and what is it based on?+
The method is traceable to authoritative sources: ACOG CO 700. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the LMP from Due Date Calculator free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is informational only. Always defer to your treating clinician or midwife for pregnancy and infant care decisions.
What can I use the LMP from Due Date Calculator for?+
It's commonly used for lmp from due date, lmp calculator, last period from edd. Reconstruct the LMP your provider's dating implies — useful for forms, apps and cross-checking records.
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