# Fundal Height Calculator

URL: https://speedycalculator.com/calculators/health/fundal-height/
Last updated: 2026-10-30

> The fundal height calculator compares the measured fundal height (from the pubic bone to the top of the uterus) with the expected value for the week of pregnancy, and flags measurements outside the usual ±2 cm range.

## Inputs

- Weeks pregnant
- Measured fundal height (cm)

## Results

- Expected range from
- Expected range to
- Difference from expected
- Result

## Formula

```
From 24 weeks: expected fundal height (cm) ≈ gestational age in weeks
Normal range ≈ weeks ± 2 cm (± 3 cm after 36 weeks)
```

## Explanation

Fundal height is a simple way to check the baby's growth at antenatal appointments. A measurement more than 2 cm off can point to a small or large baby, too much or too little amniotic fluid, or a dating error, and is usually checked with an ultrasound.

### How to use the Fundal Height Calculator

- **Weeks pregnant**
- **Measured fundal height**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter how many weeks pregnant you are and the fundal height your midwife measured.

### Inputs explained

FieldWhat to enterWeeks pregnantA numberMeasured fundal heightIn cm
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Weeks pregnant: 30; Measured fundal height: 29 cm.

Results — Expected range from = 28 cm; Expected range to = 32 cm; Difference from expected = -1 cm; **Result = Within the expected range**.

## Key terms

- **Fundal height**: Distance from the pubic bone to the top of the uterus.

## FAQ

**When is fundal height measured?**
At each antenatal visit from about 24 weeks.

**Why might fundal height be off?**
Baby size, amniotic fluid, the baby's position, maternal weight or a wrong due date.

**Is fundal height accurate in obesity or twins?**
Less so; ultrasound is used instead.


## Sources

- [NICE guideline NG201 – Antenatal care](https://www.nice.org.uk/guidance/ng201)
- [RCOG Green-top Guideline 31 – Small-for-gestational-age fetus](https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/)