How Many Months Are 27 Weeks Pregnant? | The Sixth Month

At 27 weeks pregnant, you are in the sixth month of pregnancy (roughly 6 ¼ months), still in the second trimester with the third trimester beginning.

You’ve probably run into the question at a baby shower or from a curious relative. When someone asks how many months you are, the weeks-to-months conversion feels surprisingly tricky. It doesn’t help that a calendar month can be 28, 30, or 31 days, while pregnancy weeks are measured strictly from your last menstrual period.

So where does 27 weeks actually land? The short answer is that 27 weeks pregnant falls in the sixth month — specifically at the end of month 6, just a week away from entering the third trimester. Here’s what that means for you and your baby.

From Weeks to Months: Where 27 Falls

Pregnancy is officially counted as 40 weeks from the first day of your last period, which works out to a little more than nine calendar months. Because months vary in length, the week-by-month breakdown is an estimate rather than a perfect fit.

Medical sources generally agree that 27 weeks places you in the sixth month of pregnancy. The What to Expect guide puts you at week 27 of month 6, while the Happiest Baby resource describes it as 6 ¼ months along.

This is also the final week of the second trimester. The third trimester officially begins at week 28, which starts month 7. So at 27 weeks, you’re in a transitional window — still technically in the second trimester but only days away from the home stretch.

Why the Weeks-to-Months Confusion Sticks

It’s easy to see why people get mixed up. Four weeks looks like one month on paper, but that math adds up to only 28 days — short of a full calendar month. Over 40 weeks, the difference accumulates, leading to confusion at key checkpoints like week 27.

Here are some of the main reasons the conversion can feel off:

• Month length varies: February can be 28 days; January is 31. Pregnancy months are not locked to the calendar, so week 27 might land in the middle of a calendar month.
• Counting from LMP versus conception: The 40-week count includes two weeks before ovulation. That pushes the gestational age forward, making the relationship between weeks and months approximate.
• Pregnancy isn’t exactly nine months: 40 weeks equals 9.2 calendar months on average, so the “nine months” tag is a simplification that breaks down when you try to assign exact month numbers to each week.
• Trimesters are uneven: The first trimester lasts about 3.5 months (weeks 1–14), the second about 3.5 months (weeks 15–27), and the third about 3 months (weeks 28–40). Month boundaries don’t align neatly with week numbers.

Because of these wrinkles, most healthcare providers prefer to talk in weeks rather than months. But when you need a quick answer, 27 weeks is generally considered your sixth month of pregnancy.

Your Baby at 27 Weeks: What’s Developing

At this stage, your baby is moving past the three-pound mark and all five senses are fully developed. The lungs are capable of functioning with medical support if needed, and around this time babies can open and close their eyes.

Size-wise, the NHS describes your baby as about 36.6 cm (14.4 inches) from head to heel — roughly the size of a head of cauliflower or a honeydew melon. UnityPoint Health adds that babies at this week are gaining nearly half a pound per week, so growth is accelerating.

For a full week-by-week breakdown of size and milestones, check the baby size 27 weeks page from the NHS. It details what’s happening inside your body this week and what you can expect at your next prenatal visit.

In addition to these milestones, your baby is practicing breathing movements, hiccupping, and responding to sounds from the outside world. Movement patterns may become more noticeable as space inside the uterus becomes cozier.

Common Discomforts at 27 Weeks and How to Manage Them

As your body adjusts to a growing belly, you may experience a few familiar pregnancy symptoms. The NHS lists tiredness and sleep difficulties, stretch marks, swollen or bleeding gums, and round ligament pains among the common discomforts at 27 weeks.

1. Sleep problems: Finding a comfortable position can be harder. A pregnancy pillow or extra pillows between your knees may help support your belly and hips.
2. Stretch marks: As skin stretches, some women develop marks on the belly, breasts, or thighs. Moisturizers won’t prevent them but can soothe itching.
3. Gum sensitivity: Pregnancy hormones can make gums swell and bleed more easily. Gentle brushing and regular dental checkups are recommended.
4. Round ligament pain: Sharp or achy sensations on the side of the belly are common as ligaments stretch. Changing positions slowly can help ease the discomfort.

If any symptom becomes severe or persistent, it’s always a good idea to mention it to your midwife or obstetrician. Many discomforts can be managed with small adjustments, but it’s important to rule out other causes.

Preparing for the Transition to the Third Trimester

With week 28 just around the corner, you’re about to enter the third trimester. Mayo Clinic describes fetal activity at this stage as becoming more distinct — kicks, stretches, and grasping movements become stronger. You may notice that your baby has a preferred time of day for activity.

Your provider will likely begin more frequent checkups starting next month, including glucose screening tests and checks for your blood pressure and iron levels. It’s a good time to start thinking about your birth plan and any classes you want to take before the due date.

For a detailed look at fetal movement and development in the weeks ahead, the baby movements 27 weeks guide from Mayo Clinic covers what to expect as your baby grows stronger and more coordinated.

These approximations are based on typical obstetric conversions. Keep in mind that individual pregnancies vary, and your provider will use weeks and due dates rather than months to track your progress.

The Bottom Line

At 27 weeks pregnant, you are in the sixth month of pregnancy — about 6 ¼ months along. This week marks the end of the second trimester and the doorstep of the third trimester (starting at week 28). While the weeks-to-months conversion isn’t exact due to variable month lengths, all major medical sources place 27 weeks in month 6.

Your obstetrician or midwife can clarify where you are in the timeline and help you plan for the third-trimester screenings ahead. If you have questions about your specific due date or baby’s growth pattern, your healthcare team is the best resource for individualized guidance.