Check if your fundal height measurement matches your gestational age. Expected cm equals GA weeks (±2 cm) for weeks 20-36.
Fundal height — the distance from the pubic bone to the top of the uterus — is a simple but valuable tool for monitoring fetal growth during pregnancy. Measured in centimeters with a tape measure, fundal height closely tracks gestational age in weeks between 20 and 36 weeks of pregnancy.
A general rule of thumb is that fundal height in centimeters should approximately equal the gestational age in weeks, with a normal variation of ±2 cm. For example, at 28 weeks, a fundal height of 26-30 cm is considered normal. Measurements outside this range may prompt further evaluation with ultrasound.
This calculator helps you interpret your fundal height measurement by comparing it to the expected range for your gestational age. While it does not replace clinical assessment, it helps you understand what your provider is measuring and what the numbers mean. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation.
Fundal height measurement is a quick, non-invasive way to screen for growth abnormalities between ultrasound appointments. A measurement that is too small may indicate intrauterine growth restriction, while one that is too large may suggest macrosomia, polyhydramnios, or incorrect dating. Understanding your measurement empowers you to have informed conversations with your provider.
Expected Fundal Height (cm) ≈ Gestational Age (weeks) Normal Range: GA weeks ± 2 cm For weeks 20-36: Low = GA − 2 Expected = GA High = GA + 2
Result: Within normal range (26-30 cm)
At 28 weeks gestational age, the expected fundal height is 28 cm with a normal range of 26-30 cm. A measurement of 27 cm falls within this range, indicating normal fetal growth. No additional testing is typically needed.
Fundal height measurement has been a cornerstone of prenatal care for decades. It provides a quick screen between ultrasound appointments and helps providers track growth trends. Serial measurements plotted on a chart reveal whether the baby is growing consistently.
Several factors can affect measurement accuracy: maternal BMI (higher BMI may lead to larger measurements), fetal position (breech babies may measure differently), multiple gestation, and fibroids. After 36 weeks, engagement of the fetal head in the pelvis can reduce the measurement.
If two consecutive fundal height measurements fall outside the expected range, your provider will typically order an ultrasound to assess fetal weight, amniotic fluid levels, and placental function. This step ensures that any growth concerns are identified and managed promptly.
Fundal height (also called symphysis-fundal height or SFH) is the distance from the top of your pubic bone to the top of your uterus. It is measured in centimeters using a tape measure during prenatal visits.
Between 20-36 weeks, the uterus grows at a remarkably consistent rate of about 1 cm per week. This correlation makes fundal height a convenient screening tool for fetal growth.
A measurement more than 2 cm below expected may indicate slow fetal growth (IUGR), low amniotic fluid, or incorrect dating. Your provider may order an ultrasound to investigate. One small measurement alone is rarely cause for alarm.
A measurement more than 2 cm above expected may suggest a large baby (macrosomia), excess amniotic fluid (polyhydramnios), twins, or uterine fibroids. An ultrasound can help determine the cause.
You lie on your back with an empty bladder. Your provider places a tape measure at the top of the pubic bone and extends it to the top of the uterus (fundus). The measurement is recorded in centimeters.
While you can attempt it, clinical measurement is more accurate because providers are trained to identify the fundal landmark. At-home measurement can give a rough estimate but should not replace prenatal visits.