EDD Calculator — Estimated Due Date
Enter the number of days since the first day of your last menstrual period (LMP) and your typical cycle length to find your estimated due date, how many weeks pregnant you are, and which trimester you're in.
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Currently 8w 0d pregnant — First trimester (weeks 1–13)
- 1
Adjusted pregnancy duration
280 + (28 − 28) = 280Naegele's rule base of 280 days adjusted for your cycle length. - 2
Trenutna gestacijska starost
56 ÷ 7 = 8 weeks + 0 days - 3
Days remaining until EDD
280 − 56 = 224
Kako deluje ta kalkulator?
EDD = first day of LMP + 280 days (adjusted for cycle length). Divide days since LMP by 7 for current pregnancy week. The due date is an estimate — most births occur in the 37–42 week window, and first-trimester ultrasound dating may be more precise. Naegele's rule assumes a standard 28-day cycle.
Formula
How this is calculated
Naegele's rule — the standard clinical method — estimates the due date as 280 days (40 weeks) after the first day of the last menstrual period. This assumes a 28-day cycle with ovulation on day 14. If your cycle differs, the calculator adjusts by adding or subtracting the difference from 28: a 30-day cycle adds 2 days, a 26-day cycle subtracts 2 days.
The pregnancy is divided into three trimesters: the first covers weeks 1–13 (days 0–97 from LMP), the second weeks 14–27 (days 98–195), and the third weeks 28 onward. The timeline bar shows how far along you are as a fraction of the full adjusted pregnancy duration.
The estimated due date is a statistical median — only about 5 % of babies arrive exactly on it. Actual delivery occurs anywhere in the 37–42 week window in the majority of pregnancies. Your healthcare provider may revise the EDD with ultrasound measurements, which can be more accurate than date-based estimation especially in the first trimester.
Pogosta vprašanja
Naegele's rule is accurate to within about ±2 weeks for most pregnancies. A first-trimester ultrasound can narrow this to ±5–7 days. Only about 5 % of births happen on the calculated EDD itself, with most occurring within the 37–42 week window.
LMP stands for last menstrual period — its first day is the standard starting point for pregnancy dating, because ovulation and conception dates are usually unknown. The 280-day window accounts for roughly 14 days of the follicular phase before ovulation plus 266 days of embryonic development.
Yes. A woman with a 35-day cycle likely ovulates around day 21 rather than day 14, placing conception about 7 days later — so the EDD shifts by the same amount. Adjust the cycle-length input for a better personalised estimate.
Znano tudi kot
TG we-Calculate Editorial Team. (2026). EDD Calculator — Estimated Due Date [Online calculator]. TG we-Calculate. https://we-calculate.com/sl/calculator/edd-calculator
TG we-Calculate Editorial Team. "EDD Calculator — Estimated Due Date." TG we-Calculate. 2026. https://we-calculate.com/sl/calculator/edd-calculator.
TG we-Calculate Editorial Team, "EDD Calculator — Estimated Due Date," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/sl/calculator/edd-calculator
@misc{wecalculate_edd_calculator, title = {EDD Calculator — Estimated Due Date}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/sl/calculator/edd-calculator}}, year = {2026}, note = {TG we-Calculate} }
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