LMP Apr 1, 2026, 28 day cycle
- Gestational age today
- 10w 4d
- Estimated conception
- Apr 15, 2026
- Trimester
- First trimester
Due Date Calculator
Use this free due date calculator to estimate expected delivery date from the first day of the last period and cycle length.
Estimate, not diagnosis Formula notes Example inputs Tab-only history
Formula steps
- Start with the first day of the last menstrual period.
- Add 280 days, adjusting for cycle length compared with a 28-day cycle.
- Estimate conception near ovulation, about 14 days before the next period.
How to use the Due Date Calculator
- Enter the requested measurements, dates, lab values, or workout details.
- Check that the units and formula assumptions match what the tool is asking for.
- Press the calculate button to see the answer, supporting metrics, and formula steps.
- Read the estimate with the health disclaimer in mind, then copy the result if you need it for notes.
What people use it for
Estimate a due date from last menstrual period.
Adjust the estimate for shorter or longer cycles.
Find estimated conception date alongside due date.
Use as a planning reference before clinical confirmation.
Quick examples
LMP Apr 1
28-day cycleEstimated due date Jan 6, 2027
32-day cycle
Due date moves laterCycle-adjusted estimate
26-day cycle
Due date moves earlierCycle-adjusted estimate
Need the guide or a nearby tool?
Need a slower walkthrough, a related calculator, or the full library? These links keep you close to the task you started.
- How to use the Due Date Calculator See slower examples, input meanings, formula notes, result limits, and mistakes to avoid.
- Health & Fitness Browse related calculators and utilities in the same category.
- Calculator and utility guides Find more guides that use real tool inputs and example numbers.
- All free tools Search every live tool, converter, calculator, AI helper, and browser utility.
Frequently asked questions
Plain-language answers about when to use the estimate, what the formula means, what it cannot decide for you, and how privacy works.
When should I use the Due Date Calculator?
Use it for simple educational checks, trend tracking, or planning tasks like these: Estimate a due date from last menstrual period. Adjust the estimate for shorter or longer cycles. It can help you understand a number, but it cannot explain your whole health situation.
What do the main Due Date Calculator inputs mean?
Enter the body, activity, date, or lab values exactly in the units shown on the page. Height, weight, age, sex, time, and activity level can change health estimates a lot, so treat each label like a rule instead of a suggestion. If you are unsure which option fits, choose the closest honest match and read the result as a rough estimate.
What is the Due Date Calculator doing with my inputs?
In plain language: The calculator uses Naegele-style dating: LMP plus 280 days, adjusted by the difference from a 28-day cycle. Read the result together with the notes on the page, because health and fitness numbers often need personal context.
How should I read the Due Date Calculator result?
Use the result as a learning number, not a final answer about your body or health. The supporting lines can show categories, ranges, calories, dates, or targets, but those numbers still need context like age, medical history, pregnancy status, training level, and advice from a qualified professional.
Can I use this as medical advice?
No. This page provides an educational estimate only. Talk with a qualified health professional before making medical, pregnancy, nutrition, medication, or safety decisions. Use the calculator as a learning tool, then ask a qualified professional about decisions that affect care, pregnancy, medication, nutrition, or safety.
What should I double-check before trusting the result?
Check the units, date, and personal details before reading the answer. For example, pounds and kilograms, inches and centimeters, or a wrong activity level can change the result quickly. If the number feels surprising, rerun it slowly and compare it with the examples.
Does the site save my health inputs?
No. The calculator runs in your browser tab. Recent answers stay only on the page while you use it, and they are not sent to a server.