Pregnancy Due Date Calculator

Calculate your baby's due date and track your pregnancy

About the Calculator

Expectant parents need a clear due date and pregnancy timeline. This calculator supports four methods: Last Menstrual Period (LMP), Conception Date, Ultrasound Date, and IVF Transfer Date. Get your estimated delivery date, current week, key milestones, and prenatal appointment schedule. All calculations run in your browser - no data is stored. Use the Pregnancy Due Date Calculator to get a clear result you can act on right away. This calculator is designed to be practical, fast, and easy to use on any device. If you are comparing options, run a few scenarios to see how small changes affect the outcome.

Calculate from

Last Menstrual Period (LMP)Conception / Ovulation DateUltrasound DateIVF Transfer Date

First day of last menstrual period

Average cycle length (optional)

days (21-35, default 28)

Pregnancy week-by-week guide

First trimester (1–13)

Second trimester (14–27)

Third trimester (28–42)

Pregnancy week-by-week: full reference

Week	Baby size	Baby's development	You might experience
1	poppy seed 🌱	-	-
2	orange seed 🍊	-	-
3	pinhead •0.1 mm	Fertilization occurs Cell division begins	Possible implantation spotting
4	poppy seed 🌱2 mm	Blastocyst implants Placenta begins forming	Missed period Early pregnancy signs
5	sesame seed ⚪3 mm	Neural tube forming Heart tube developing	Fatigue Tender breasts Nausea may start
6	lentil 🫘5-6 mm	Heart begins beating Arm and leg buds appear	Morning sickness Fatigue Frequent urination
7	blueberry 🫐10 mm	Brain developing rapidly Facial features forming	Nausea Food aversions Mood swings
8	raspberry 🍇16 mm	All major organs forming Fingers and toes webbing	Continued nausea Fatigue Bloating
9	grape 🍇23 mm	External genitals developing Baby can move	Morning sickness peaks Fatigue Breast changes
10	strawberry 🍓1.2 in (3.1 cm) · 0.14 oz (4 g)	All vital organs formed Fingers and toes distinct Bones beginning to harden Can make small movements	Morning sickness may peak Increased urination Fatigue Food aversions or cravings
11	lime 🍋1.6 in (4.1 cm) · 0.25 oz (7 g)	Baby breathing amniotic fluid Nails beginning to form	Nausea may ease Growing uterus Fatigue
12	plum 🍑2.1 in (5.4 cm) · 0.5 oz (14 g)	Reflexes developing Vocal cords forming	Nausea often improves Energy may return Bump may appear
13	peach 🍑2.9 in (7.4 cm) · 0.8 oz (23 g)	First trimester complete Fingerprints forming	Energy returning Reduced nausea Increased appetite
14	lemon 🍋3.4 in (8.7 cm) · 1.5 oz (43 g)	Baby can suck thumb Lanugo (fine hair) appears	More energy Glowing skin Second trimester begins
15	apple 🍎4 in (10.1 cm) · 2.5 oz (70 g)	Hearing developing Legs lengthening	Round ligament pain Nasal congestion
16	avocado 🥑4.6 in (11.6 cm) · 3.5 oz (100 g)	Baby can hear Eyes moving	Feeling baby move (possible) Backaches
17	pear 🍐5.1 in (13 cm) · 5 oz (140 g)	Fat storing begins Skeleton hardening	Increased appetite Stretch marks may appear
18	sweet potato 🍠5.6 in (14.2 cm) · 6.7 oz (190 g)	Baby can yawn Hiccups begin	Feeling movements Bump more visible
19	mango 🥭6 in (15.3 cm) · 8.5 oz (240 g)	Senses developing Vernix forming	Stronger kicks Skin changes
20	banana 🍌6.5 in (16.4 cm) · 10.6 oz (300 g)	Halfway point Baby swallows	Definite movements Belly button may pop
21	carrot 🥕7 in (17.8 cm) · 12.7 oz (360 g)	Bone marrow making blood Eyebrows visible	Braxton Hicks may start Back pain
22	papaya 🥭7.6 in (19.3 cm) · 15.2 oz (430 g)	Viable outside womb Sleep-wake cycles	Baby responds to sound Linea nigra may appear
23	large mango 🥭8 in (20.3 cm) · 1.1 lb (500 g)	Rapid brain growth Audible heartbeat	Swollen ankles Heartburn
24	corn 🌽8.5 in (21.6 cm) · 1.3 lb (600 g)	Viability milestone Lungs developing	Glucose screening window (24-28) More frequent movements
25	rutabaga 🥬9 in (22.9 cm) · 1.5 lb (660 g)	Responds to your voice Hand preference may show	Shortness of breath Sleep issues
26	lettuce 🥬9.4 in (23.9 cm) · 1.7 lb (760 g)	Eyes opening Eyelashes formed	Braxton Hicks Leg cramps
27	cauliflower 🥦9.6 in (24.5 cm) · 2 lb (900 g)	Second trimester ends Brain very active	Third trimester begins Growing discomfort
28	eggplant 🍆10 in (25.4 cm) · 2.2 lb (1 kg)	Eyes can blink Dreaming begins	Tdap vaccine recommended Weekly kick counts
29	butternut squash 🎃10.5 in (26.7 cm) · 2.5 lb (1.2 kg)	Bone marrow produces red blood cells Head growing	Breathlessness Insomnia
30	cabbage 🥬10.8 in (27.5 cm) · 3 lb (1.4 kg)	Brain wrinkles developing Body fat increasing	Frequent urination Pelvic pressure
31	coconut 🥥11.2 in (28.5 cm) · 3.3 lb (1.5 kg)	All five senses working Can turn head	Braxton Hicks increase Back pain
32	jicama 🥔11.5 in (29.3 cm) · 3.8 lb (1.7 kg)	Toenails visible Lanugo shedding	Belly measuring Fatigue returns
33	pineapple 🍍11.8 in (30 cm) · 4.2 lb (1.9 kg)	Pupils react to light Immune system developing	Shortness of breath Swelling
34	cantaloupe 🍈12 in (30.5 cm) · 4.7 lb (2.1 kg)	Lungs nearly mature Skin smoothing	Nesting instinct Braxton Hicks
35	honeydew 🍈12.3 in (31.3 cm) · 5.3 lb (2.4 kg)	Kidneys fully developed Liver processing waste	Pelvic pressure Discomfort
36	papaya 🥭12.6 in (32 cm) · 5.8 lb (2.6 kg)	Weekly checkups begin Baby may drop	Baby dropping Lightening
37	swiss chard 🥬13 in (33 cm) · 6.3 lb (2.9 kg)	Full term Ready for birth	Mucus plug may pass Nesting
38	leek 🧅13.2 in (33.5 cm) · 6.8 lb (3.1 kg)	Organ systems ready Continuing to gain weight	Waiting for labor Anticipation
39	mini watermelon 🍉13.4 in (34 cm) · 7.3 lb (3.3 kg)	Skin becoming paler Vernix mostly gone	Signs of labor Patience
40	watermelon 🍉14 in (35.6 cm) · 7.5 lb (3.4 kg)	Due date Baby is ready	Any day now Labor signs
41	watermelon 🍉14.2 in (36 cm) · 7.9 lb (3.6 kg)	Post-due Still developing	Post-term monitoring Induction discussion
42	watermelon 🍉14.4 in (36.6 cm) · 8.1 lb (3.7 kg)	Post-term Induction likely	Closely monitored Induction common

Important

This calculator provides estimates only and should not replace medical advice. Only about 5% of babies are born on their exact due date. Your healthcare provider will confirm your due date. Ultrasound dating (especially first trimester) is most accurate. If you have irregular cycles, LMP-based calculations may be less accurate. This tool is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Formulas

The Formula

LMP: Due Date = LMP + 280 days Conception: Due Date = Conception + 266 days Ultrasound: remaining days to 280 added to scan date IVF Day 5: Transfer + 261 days

Glossary

Tips & Strategies

Quick tip. Only about 5% of babies are born on their exact due date.

Quick tip. First trimester ultrasound is the most accurate dating method.

Quick tip. Your healthcare provider will confirm your due date at your first visit.

If you have irregular cycles. LMP-based due dates may be less accurate.

Cross-check when the decision matters. Run a second scenario with rounded inputs or a different path to the same quantity so you do not rely on a single fragile chain of arithmetic.

🎉 Fun Facts

•Naegele's Rule (LMP + 280 days) dates to 1812 and was named after German obstetrician Franz Naegele.
•The 40-week pregnancy is measured from the first day of your last period, so you're "2 weeks pregnant" at conception.
•Full term is 37-42 weeks; most babies arrive between 39-41 weeks.
•IVF pregnancies are dated from embryo age, making due dates very precise.