FREE ONLINE TOOL · FITNESS & HEALTH CALCULATORS

Due Date Calculator

Estimate an expected due date from the last menstrual period or a known conception date.

Instant resultsFree to useNo account required
Calculator inputs

Enter your values to calculate an estimate.

Results update as you change inputs. Check the assumptions and formula below before using an estimate for a financial, health or academic decision.

Your results

Calculated from the values entered.

Estimate

Estimated due date

2027-07-08

Dating method

Last menstrual period

Estimated pregnancy duration

280 days

Calculations run in your browser. Values are not sent to FastSEOHub.

What is a due date?

An estimated due date is a planning estimate, not a prediction of the exact delivery day. This tool supports dating from the first day of the last menstrual period or from an estimated conception date. Clinical dating may be adjusted after an ultrasound or professional assessment.

Formula and calculation method

LMP method: due date = LMP + 280 days. Conception method: due date = conception date + 266 days.

The result is only as reliable as the inputs and assumptions. This tool is educational and does not replace professional financial, medical, legal or academic advice.

How to use this calculator

  1. Enter the values requested in the calculator.
  2. Review the result panel; it updates when an input changes.
  3. Change one assumption at a time to compare scenarios.
  4. Check the formula and limitations before acting on the estimate.

Frequently asked questions

Is this due date calculator free?

Yes. You can use this calculator in your browser without creating an account.

How accurate is the result?

It applies the displayed formula to the values you provide. Real-world outcomes can differ because of fees, changing rates, individual circumstances or rules not represented in this estimate.

Are my inputs stored?

No. The calculation runs locally in your browser and the values are not submitted to FastSEOHub.

Back to all calculators