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Compares a fundal height measurement (cm, from pubic bone to top of uterus) against the standard obstetric rule-of-thumb: between roughly 20 and 36 weeks of gestation, fundal height in centimeters roughly equals the number of weeks of gestation, plus or minus about 2 cm. This is a rough screening reference only — for general reference and educational purposes, not a diagnostic tool. Consult a doctor for actual prenatal assessment, since factors like fetal position, multiples, and maternal build affect fundal height.
How it works
Enter your fundal height measurement in centimeters and your current gestational week. The tool compares the two and notes whether the difference falls within the commonly cited ±2 cm range.
- Enter fundal height measurement (cm).
- Enter gestational week.
- Click Calculate to see your results.
Examples
Fundal height 28 cm at 28 weeks
Difference = 0 cm — within the commonly cited ±2 cm range.
Who should use it
- Reviewing a prenatal visit measurement at home for reference.
- Prenatal care education about fundal height screening.
Industry applications
- Prenatal care and midwifery reference
- Obstetric nursing education
Advantages
- Quick, simple screening reference used widely in prenatal care.
- No special equipment needed beyond a measuring tape.
Limitations
- Not reliable outside the roughly 20-36 week window.
- Affected by many non-clinical factors (maternal build, fetal position, multiples).
Common mistakes to avoid
- Applying the rule outside the roughly 20-36 week window where it is commonly cited.
- Treating a single out-of-range measurement as diagnostic rather than a screening prompt.
Best practices
- Track fundal height trends over several prenatal visits rather than relying on one measurement.
Tips
- If a measurement seems off, your provider will typically follow up with an ultrasound rather than relying on fundal height alone.