Pregnancy Due Date Calculator: Estimate Your Baby's Arrival
Author: Ian C. Langtree - Writer/Editor for Disabled World (DW)
Published: 2017/12/21 - Updated: 2026/01/16
Publication Type: Charts, Graphs, Tables
Category Topic: Calculators - Charts - Related Publications
Page Content: Synopsis - Introduction - Main - Insights, Updates
Synopsis: This pregnancy calculator provides expectant parents with medically-based pregnancy calculations that follow standard obstetric protocols used by healthcare providers worldwide. The calculator determines estimated due dates by applying the established 280-day formula from the first day of the last menstrual period, offering useful data points including conception dates, trimester endpoints, and current pregnancy week counts. Women with disabilities who may face additional prenatal monitoring requirements will find this particularly valuable for tracking appointments and planning accommodations, while the tool's accessibility benefits anyone seeking to understand their pregnancy timeline without scheduling an immediate office visit. The calculator accounts for variable menstrual cycle lengths and acknowledges biological realities like sperm viability, making it a practical reference point between medical consultations - Disabled World (DW).
Introduction
Our pregnancy calculator will provide you with a close estimate of the due date of your baby and several other interesting dates including date of conception, end of your first and second trimester, the date your child is due on, and the number of weeks you have been pregnant for.
Main Content
Doctors use the first day of your last menstrual period to calculate your estimated due date, however other factors can influence the babies arrival date. The formula to estimate the due date of a baby is calculated by adding 266 days to ovulation (Ovulation Calculator), or 280 days to the first day of your last menstrual cycle.
Pregnancy Calculator*
*Only your physician can accurately determine your due date or the date of your conception based on his/her knowledge of your complete medical condition.
Who Got Me Pregnant Calculator...
Several women have emailed us and asked if our pregnancy calculator will tell them, "who got me pregnant?" Well, the answer is the calculator cannot name who may have gotten you pregnant, however, by inputting the information required - and even trying other close dates (That's dates as in days, not who you went out with...), you may be able to narrow it down quite a bit. Good luck!
Our pregnancy calculator WILL provide you with a close estimate of;
- The due date of your baby.
- Date of conception.
- End of your first and second trimester.
- The date your child is due on.
- The number of weeks you have been pregnant for.
This is the way most doctors calculate a due date without an ultrasound.
Notes:
Human female pregnancy lasts 40 weeks on average. However, do not forget that the average month is 4 weeks and several days long - not four weeks exactly. It is for this reason that doctors calculate how many weeks pregnant you are, as measuring pregnancy by weeks is a far more accurate means to determine length of pregnancy.
Your babies due date can never be predicted precisely, even when the exact date of conception is known.
There are several variables that can affect the date given as your babies due date. For instance menstrual cycles can last from 22 days to as many as 44 days, so to obtain reasonably accurate results you will need to enter the average number of days in your menstrual cycle in the pregnancy calculator.
Another factor that can influence your babies birth date is the fact that you may not have conceived on the day you had intercourse! Human sperm can actually survive in a womans uterus for up to 3 days after sex.
Your doctor will help you obtain the most accurate estimated date of conception or due date.
Choosing Babys Sex at Conception - Various ways to try, including the Shettles Method, to conceive a boy or girl baby, includes baby gender predictor calculator.
Insights, Analysis, and Developments
Editorial Note: While digital pregnancy calculators offer convenient preliminary estimates, they represent starting points rather than definitive answers in prenatal care. Every pregnancy unfolds according to its own biological clock, influenced by factors ranging from cycle irregularities to the timing of ovulation and implantation. Healthcare providers combine these mathematical projections with ultrasound measurements, physical examinations, and individual health histories to refine predictions throughout pregnancy. For women managing chronic conditions or disability-related health concerns, these tools serve best as organizational aids that complement - never replace - the personalized guidance of obstetricians and midwives who understand the complete clinical picture. The real value lies not in pinpoint accuracy but in helping expectant families grasp the general progression of pregnancy stages and prepare accordingly - Disabled World (DW).
Author Credentials: Ian is the founder and Editor-in-Chief of Disabled World, a leading resource for news and information on disability issues. With a global perspective shaped by years of travel and lived experience, Ian is a committed proponent of the Social Model of Disability-a transformative framework developed by disabled activists in the 1970s that emphasizes dismantling societal barriers rather than focusing solely on individual impairments. His work reflects a deep commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.