How is my due date calculated?

The calculator uses the first day of your last menstrual period (LMP) and adds 280 days (40 weeks) to estimate your due date. This is the standard Naegele's rule, assuming a regular 28-day cycle.

Can I find out my conception date?

Yes, the calculator estimates your conception date by subtracting 266 days (38 weeks) from your due date, which is the average time from conception to birth. This is an estimate, as conception can vary by a few days.

What if my cycle is irregular?

The calculator assumes a regular 28-day cycle. If your cycle is longer or shorter, your due date may differ. For the most accurate estimate, consult your healthcare provider, who may use ultrasound measurements.

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Дата предполагаемых родов.

4 авг. 2026 г.

Рассчитаите предполагаемую дату родов на основе последнеи менструации

Этот калькулятор пока переведён не полностью — часть текста отображается на английском.

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Введите значения

Результаты обновляются во время ввода.

02 / ОТВЕТ

Последняя менструация

Введите первый день последней менструации. Оценка предполагает регулярный 28-дневный цикл и 280-дневную беременность.

Первый день последней менструации

Примечание: Это оценка, а не предсказание. Лишь небольшая часть родов происходит точно в расчётную дату, а врач может определить более точную дату по УЗИ.

Расчётная дата родов

August 18, 2027

280 дней осталось

Текущий прогресс

0w 0d

Триместр

1st

Прогресс0%

Расчётная дата зачатия: ~11/25/2026

Прошло времени: 0 недель

Следующая веха: Начало второго триместра

Cite this calculator

Canonical URL: https://mathify.one/ru/health/due-date

Updated 4 авг. 2026 г.

Cite as: Mathify. (2026). Дата предполагаемых родов. https://mathify.one/ru/health/due-date

Use Cases

Plan for your baby's arrival

Know your estimated due date to plan maternity leave, prepare the nursery, and schedule prenatal appointments.

Example: Enter your LMP to see your due date and current pregnancy week.

Track pregnancy progress

Monitor how far along you are and what to expect each week, helping you stay informed about your baby's development.

Example: At 20 weeks, you're halfway through your pregnancy.

Frequently Asked Questions

How is my due date calculated?: The calculator uses the first day of your last menstrual period (LMP) and adds 280 days (40 weeks) to estimate your due date. This is the standard Naegele's rule, assuming a regular 28-day cycle.
Can I find out my conception date?: Yes, the calculator estimates your conception date by subtracting 266 days (38 weeks) from your due date, which is the average time from conception to birth. This is an estimate, as conception can vary by a few days.
What if my cycle is irregular?: The calculator assumes a regular 28-day cycle. If your cycle is longer or shorter, your due date may differ. For the most accurate estimate, consult your healthcare provider, who may use ultrasound measurements.

Tips & Common Mistakes

Tips

Enter the first day of your last menstrual period accurately for the best estimate.
Remember that only about 5% of babies are born on their exact due date; it's normal to give birth a week or two before or after.
Use the conception date estimate to understand your pregnancy timeline, but rely on ultrasound for precise dating.
If your cycle is longer than 28 days, your due date may be later; consider discussing with your doctor.

Common Mistakes to Avoid

Using the date your period ended instead of the first day of your last period.
Assuming the due date is exact; it's an estimate and can change based on ultrasound findings.
Forgetting to account for irregular cycles, which can affect the accuracy of the calculation.

Last updated: August 13, 2026