Fundal Height Calculator

Fundal height is measured in centimeters using the symphysis-fundal height (SFH). The underlying mathematical models estimate gestational age or fetal percentile based on established obstetric equations. For example, the expected median SFH can be modeled as medianSFH = 5.1333 + (0.1058 * (GA^2)) - (0.02312 * (GA^2)) * ln(GA), where GA represents gestational age in weeks. Standard deviations and percentile ranks are subsequently derived to determine if the measurement falls within the typical healthy range for a given week of pregnancy.

Imagine an expectant mother who is exactly 28 weeks along in her pregnancy (GA = 28). During a routine prenatal checkup, her healthcare provider measures her symphysis-fundal height (SFH) at 27 centimeters. Using our formula, the median expected SFH for 28 weeks is approximately 28.2 centimeters with a standard deviation of about 1.7 centimeters. By inputting these metrics into the tool, the calculator determines that her measurement sits comfortably within the normal middle percentile range, indicating healthy and steady fetal development without requiring immediate clinical intervention.

Always empty your bladder immediately prior to measurement, as a full bladder can artificially elevate the uterine position. Ensure you lie flat on your back on an examination table to maintain a consistent posture for every measurement. Keep in mind that individual variations such as maternal body mass index, amniotic fluid volume, and fetal position can naturally influence the reading, so consistency in who takes the measurement is key.