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Fundal Height Calculator

Health

Estimate gestational age from a measured fundal height using the common cm-equals-weeks reference guideline between 20 and 36 weeks of pregnancy.

Reviewed by the thecalcu.com team · Last updated July 22, 2026

1840

Estimated Gestational Age

28
Typical Range (Low)
26
Typical Range (High)
30

This calculator computes your Estimated Gestational Age, Typical Range (Low), Typical Range (High) from the values you enter.

Inputs
Fundal Height
Outputs
Estimated Gestational AgeTypical Range (Low)Typical Range (High)

What is a Fundal Height?

The Fundal Height Calculator estimates gestational age from a measured fundal height, using the commonly cited reference guideline that fundal height in centimetres roughly equals gestational age in weeks, between about 20 and 36 weeks of pregnancy.

For a more precise gestational age calculation, see the Gestational Age Calculator.

Why Use a Fundal Height Calculator?

Fundal height is a routine measurement at prenatal checkups, and this calculator lets you quickly translate that measurement into an estimated gestational age using the commonly referenced rule of thumb.

Who Should Use This Calculator?

  • Expecting parents wanting to understand a fundal height measurement from a recent checkup.
  • Students of nursing or midwifery learning the fundal height reference guideline.
  • Healthcare educators demonstrating fundal height estimation.
  • Anyone researching how fundal height relates to pregnancy dating methods.

What Insights Does the Fundal Height Calculator Give You?

The Estimated Gestational Age is the primary result, using the cm-equals-weeks reference guideline. The Typical Range (Low) and Typical Range (High) figures show the commonly cited ±2 cm/weeks variation around that estimate.

How to use this Fundal Height calculator

  1. Enter the fundal height measurement in centimetres.
  2. Read the Estimated Gestational Age and Typical Range instantly.
  3. Compare against other dating methods (like ultrasound dating) discussed with your healthcare provider, since fundal height is a general reference rather than a precise measurement.
Show formula & methodology ↓Show less ↑

Formula & Methodology

Estimated Gestational Age (weeks) ≈ Fundal Height (cm), valid roughly between 20-36 weeks.

Typical Range = Estimated Gestational Age ± 2 weeks

Worked example, a fundal height of 28 cm:

Estimated Gestational Age ≈ 28 weeks (typical range 26-30 weeks)

Frequently Asked Questions

What is fundal height?
Fundal height is the measured distance from the pubic bone to the top of the uterus (fundus) during pregnancy, commonly measured in centimetres at prenatal checkups from around 20 weeks onward.
How does fundal height relate to gestational age?
A commonly cited reference guideline suggests that between roughly 20 and 36 weeks of pregnancy, fundal height in centimetres approximately equals gestational age in weeks, for example, a fundal height of 28 cm roughly corresponds to 28 weeks.
Is this a precise way to determine gestational age?
No, this is a rough reference guideline, not a precise measurement. Ultrasound dating, especially from earlier in pregnancy, is generally more accurate; fundal height is more commonly used as a general growth-tracking checkpoint at routine visits.
Why might fundal height not exactly match gestational weeks?
Individual factors like the position of the baby, amount of amniotic fluid, multiple pregnancies, maternal body size, and normal measurement variation can all cause fundal height to differ from the simple cm-equals-weeks rule of thumb.
What does it mean if fundal height differs significantly from expected?
A fundal height notably outside the typical range for gestational age is one data point a healthcare provider may use alongside other information to decide whether additional monitoring, like an ultrasound, would be helpful, this calculator doesn't provide that clinical judgment.
How is fundal height measured?
It's typically measured with a flexible measuring tape from the top of the pubic bone to the top of the uterus, with the patient lying down, as part of a routine prenatal checkup.
How does this relate to the Gestational Age Calculator?
The [Gestational Age Calculator](/gestational-age-calculator/) calculates gestational age directly from days since your last menstrual period, offering a more standard dating method than the fundal height approximation used here.
Does fundal height work the same way for twin pregnancies?
No, twin and multiple pregnancies typically show a larger fundal height than the standard single-pregnancy guideline for the same gestational age, since there's more uterine content to measure.
What weeks range does this calculator apply to?
The cm-equals-weeks reference guideline is most commonly applied between roughly 20 and 36 weeks of pregnancy; outside this range the relationship becomes less reliable.
Should I track fundal height myself at home?
Fundal height measurement is typically performed by a healthcare provider using consistent technique at prenatal visits; this calculator is for general educational reference rather than a substitute for professional prenatal care.
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