Pregnancy Due Date Calculator - How Far Along Am I?

A Yes, but expect some differences. For twins, the average delivery is around 36-37 weeks, not 40. Our calculator still uses your LMP to estimate a due date, but multiples often arrive earlier. Your doctor will monitor growth closely and may schedule delivery sooner. Talk to your healthcare provider about a realistic timeline for your specific situation.

A You sure can. If your baby is already here, enter the birth date and subtract 280 days to find your estimated LMP. This reverse calculation won't tell you exactly when conception happened, but it maps the standard 40-week timeline backward. Handy for future reference or tracking another pregnancy.

A Yes, it assumes a 28-day cycle with ovulation on day 14. That's the medical standard for LMP-based calculations. If your cycle runs longer or shorter — say 32 or 24 days — your actual due date could shift by a few days. The tool doesn't adjust for cycle length automatically. Your doctor can fine-tune the date using an ultrasound around 8-12 weeks. Pro tip: check with your provider if your cycles consistently fall outside the 26-to-30-day range.

A It's an estimate — only about 4% of babies arrive exactly on their due date. The 40-week mark is more of a target than a guarantee. Most women deliver between 38 and 42 weeks. Think of your due date as a reliable guidepost for planning, not a firm deadline. Your doctor will adjust based on your baby's size and your health, so stay flexible around that window.

A If your cycle is longer than 35 days or shorter than 21, the standard 280-day calculation gets less reliable. The tool assumes ovulation at day 14, but irregular cycles shift ovulation unpredictably. For example, a 35-day cycle might push ovulation to day 21, meaning your due date could be a week later than calculated. You'll get the best accuracy by tracking ovulation signs or asking your doctor for an early ultrasound between 8 and 12 weeks.

A The due date itself never changes; that fixed date is set the moment you enter your LMP. What shifts is the 'current week' and 'trimester' display, because those update based on today's date. Return at 20 weeks and it'll show week 20, not recalculate your delivery day. If the due date itself appears different, you likely entered a new LMP by accident. Double-check the input field before saving. One quick tip: bookmark the result page or screenshot it to avoid confusion later.

A Yes, you can work backward to hit a target month. Pick your desired delivery window, then subtract 280 days to find the ideal LMP. For an August baby, you'd want your last period around late October or early November. Ovulation shifts by a few days, so aim for a two-to-three-week conception window, not a single date. This approach works best with regular cycles. If yours are irregular, ultrasound dating will override any plan you make.

A The calculator handles it, but you might see a due date that looks odd. Adding 280 days to February 29 lands you on December 5 in a non-leap year. That's mathematically correct, though some providers shift the LMP to March 1 for simplicity. Either way, your estimated due date stays within a day of the standard calculation. If you conceived via fertility treatment, don't rely on LMP at all — your clinic will set the date from the embryo transfer. When in doubt, an early ultrasound around 8 weeks settles everything.

A Using your ovulation date instead of your last menstrual period can shift your estimated due date by several days. If you ovulated on cycle day 18 instead of the standard day 14, standard tools will overestimate your gestational age. Our calculator lets you toggle input methods if you tracked basal body temperature or LH strips. But doctors usually override ovulation math with measurements from your 12-week scan anyway.

A You won't find a direct print button on the results screen. Instead, take a quick screenshot of the page on your phone or laptop. That snapshot keeps your estimated due date, current week, and trimester handy for doctor visits. Many users save the image in a dedicated pregnancy folder for quick reference during appointments.