Health Calculators
Pregnancy Calculator
Pregnancy Calculator calculate due date, estimated LMP and conception, gestational age, trimester, and milestones from five pregnancy dating methods.
Health Calculators
Pregnancy Calculator
Calculate due date, estimated LMP and conception, gestational age, trimester, and milestones from five pregnancy dating methods.
Formula
LMP due date = LMP + 280 days plus cycle adjustment; conception due = +266; ultrasound adds 280 minus measured gestational age; IVF adds 266 minus embryo age. Gestational age is elapsed days from inferred LMP.
About the Pregnancy Calculator
Calculate due date, estimated LMP and conception, gestational age, trimester, and milestones from five pregnancy dating methods. Health calculators provide a formula-based estimate for the named screening, nutrition, body, reproductive, exercise, or clinical quantity.
How the Pregnancy Calculator Works
LMP due date = LMP + 280 days plus cycle adjustment; conception due = +266; ultrasound adds 280 minus measured gestational age; IVF adds 266 minus embryo age. Gestational age is elapsed days from inferred LMP.
The calculation runs in your browser. Submitted values are validated for the required numeric range, data shape, units, and method-specific restrictions before a result is shown.
Required Inputs
- Dating method (required) Options: Last menstrual period, Known due date, Known conception date, Ultrasound date and gestational age, IVF transfer date and embryo age
- Reference date (required)
- Calculate gestational age as of (required)
- Cycle length (days) (optional)
- Ultrasound gestational weeks (optional)
- Ultrasound gestational days (optional)
- IVF embryo age at transfer (days) (optional)
Results Reported
The result panel shows the final answer together with the intermediate quantities needed to audit the calculation. Depending on this method, reported values include:
dating_methodestimated_due_dateestimated_lmp_dateestimated_conception_dateas_of_dategestational_age_daysgestational_age_weeksgestational_age_remainder_daystrimesterend_of_week_13end_of_week_27forty_week_date
Pregnancy Calculator Example
Use the example data button, calculate, then review the result table, formula, and worked solution before using the answer.
| Input | Example value |
|---|---|
| Dating method | last_period |
| Reference date | 2026-04-01 |
| Calculate gestational age as of | 2026-07-11 |
| Cycle length (days) | 28 |
| Ultrasound gestational weeks | 0 |
| Ultrasound gestational days | 0 |
| IVF embryo age at transfer (days) | 5 |
How to Use the Calculator
- Confirm that the calculator title and method match the quantity, test, conversion, or planning question you need to solve.
- Enter values with compatible units and the requested sample, group, matrix, count, date, or option format.
- Select Example Data to inspect a valid input layout, or enter your own values and select Calculate.
- Review the result table, formula, worked substitutions, warnings, and interpretation rather than using only the headline number.
- Use Copy Result or Download CSV when you need a reusable record of the displayed calculation.
Understanding the Result
These estimates are educational and are not a diagnosis or a substitute for individualized care from a qualified health professional.
Keep the entered values, units, selected options, and any warning shown beside the result. For a hypothesis test, report the statistic, degrees of freedom where applicable, p-value, alpha level, effect size, and decision. For an estimate or conversion, report the formula convention and final unit.
Accuracy and Limitations
The calculator keeps full browser precision during calculation and rounds only for display. Accuracy still depends on correct inputs and on whether the displayed model represents the real problem. Educational calculators cannot replace required professional review, current official rules, field measurements, laboratory methods, or specialist statistical software where those are necessary.
Frequently Asked Questions
What does the Pregnancy Calculator calculate?
Calculate due date, estimated LMP and conception, gestational age, trimester, and milestones from five pregnancy dating methods.
Which formula does the Pregnancy Calculator use?
LMP due date = LMP + 280 days plus cycle adjustment; conception due = +266; ultrasound adds 280 minus measured gestational age; IVF adds 266 minus embryo age. Gestational age is elapsed days from inferred LMP.
Is this a separate calculator?
Yes. This page has its own public URL, inputs, formula notes, browser function, fixture, and worked solution.
What should I verify before using the answer?
Check the entered values, units, selected options, formula convention, warnings, and result interpretation shown on this calculator page.