Fundal Height Calculator
Our fundal height calculator is an excellent tool for a variety of needs:
 Fundal height estimation based on the age of the pregnancy;
 Gestational age computed from the fundal height during pregnancy; and
 Birth weight calculations based on the fundal height by week.
Stay with us and find out how to calculate fundal height and how to measure it; we'll also talk about using our fundal height percentile calculator and how to squeeze the most out of its functions. 🤰
What is fundal height?
Fundal height is a measurement of a pregnant uterus, performed to assess fetal growth and development.
We can measure the fundal height in pregnancy by using simple tailor's tape — we need to find the length between the top of the uterus and the mother's pubic symphysis. 🤰
💡 The pubic symphysis is a joint that connects both of our pubic bones, located just above the genitalia. That's the protruding, bony part you can feel when touching the very bottom of your front torso.
How to calculate fundal height?
Fundal height is usually measured, but we can also calculate it using the age of the pregnancy — the gestational age.
Here's the exact formula that we used in our fundal height calculator:
where:
 Median SFH — short form of Median symphysisfundal height, given in centimeters (cm);
 GA — stands for the gestational age in weeks and days, turned into decimals. (e.g., 1 week 1 day = 1 ⅐ weeks = 1.14 weeks); and
 ln — a short way to write the natural logarithm.
This fundal height estimation was established by the
.How to use the fundal height calculator?
All the things you'd like to know, but you're afraid to ask, step by step!

Choose the type of calculation:
a) SFH percentile — computes the median fundal height based on your gestational age and compares it to your actual measured fundal height and its percentile.
b) SFH to gestational age — computes gestational age based on a measured fundal height.
c) SFH to fetal weight — answers the question of how to calculate baby weight by fundal height.

Input all the necessary data:
 Measured SFH — the distance between fundal height and the pubic bone, measured with the tailor's tape.
 GA weeks/days — gestational age in weeks and days.

Enjoy your results 🎉
💡 Our calculators allow you to change the unit of almost every variable, and match it to your needs! In most of the cases the calculations can be also performed both ways!
How to calculate gestational age from fundal height?
There are two different ways to complete this task:

We may use the McDonald's rule for fundal height by week:
 At 12 weeks, the uterus' fundus is located just above the pubic bone.
 During the 22nd week of pregnancy, the fundus of the uterus can be palpated at the height of the belly button.
 At 36 weeks, the fundus reaches its highest point — the bottom part of the sternum.
 The uterus then begins to move down — the baby prepares for the delivery, its head enters the birth canal.

We may also use the formula:
GA = 6.5858  2.7073 × √SFH + (1.2952 × SFH)
,where:
 GA — gestational age in weeks;
 √ — symbol of a square root; and
 SFH — symphysisfundal height given in centimeters (cm).
How to calculate baby weight by fundal height?
Fundal height during pregnancy might be an indicator for the development and wellbeing of the fetus. There are different methods that we can use for assessing the baby's weight — one of them is the fetal weight percentile calculator (the crownrump length calculations might also be of use) — another helpful and popular method is measuring the fundal height.
Here's Johnson's formula used in our fundal height — birthweight calculator:
Fetal weight = (SFH  Weight  Vertex) × 155
,
💡 This formula can be used only for babies in the vertex position (with their head down). The fetus usually takes this location after the 3336 weeks of the pregnancy.
where:
 Fetal weight — given in grams (g).
 SFH — symphysisfundal height given in centimeters (cm).
 Weight:
 Takes the value of 1, if mother weights >91 kg (200 lb).
 Takes the value of 0, if mother weight ≤91 kg (200 lb).
 Vertex — the top of the head of your baby.
 Takes the value of 12, if vertex is above ischial spine.
 Takes the value of 11, if vertex is below ischial spine.
Yay, you got it! Would you like to discover something more? 👶 We prepared some great tools that may help you deal with the pregnancy and your child's upbringing!
 Find out what's the child's birthweight percentile of your tiny human; or
 Discover the pregnancy weight gain calculator!
Fundal height measurement charts
We can use two different types of charts that describe the fundal height in pregnancy; the first one of them can be used by everyone, the second is mostly meant for medical professionals:
 The simplest fundal height measurement chart. 🍼
Gestational age  Fundal height estimation 

1214 weeks  Pubic bone (top) 
2022 weeks  Belly button 
3640 weeks  Sternum (bottom) 
3740 weeks  Uterus lowers its position 

The complex version used in the fundal height percentile calculator.
The fundal height chart, 1642 weeks of the pregnancy — all fundal heights are given in millimeters (mm).
Gestational age (exact weeks)  Centiles  

3rd  5th  10th  50th  90th  95th  97th  
16  132  135  140  158  176  181  185 
17  141  144  149  168  186  191  195 
18  150  154  159  178  196  202  205 
19  160  163  169  188  207  212  215 
20  169  173  178  198  217  222  226 
21  179  182  188  208  227  233  236 
22  188  192  198  218  238  243  247 
23  198  201  207  228  248  254  257 
24  207  211  217  238  258  264  268 
25  217  221  227  247  268  274  278 
26  226  230  236  257  279  285  289 
27  235  239  246  267  289  295  299 
28  245  249  255  277  299  305  309 
29  254  258  264  286  309  315  319 
30  263  267  273  296  318  325  329 
31  271  276  282  305  328  335  339 
32  280  284  291  314  338  344  348 
33  289  293  300  323  347  354  358 
34  297  301  308  332  356  363  367 
35  305  309  316  340  365  372  376 
36  313  317  324  349  373  380  385 
37  320  325  332  357  382  389  393 
38  328  332  339  365  390  397  402 
39  335  339  347  372  398  405  410 
40  341  346  354  380  405  413  418 
41  348  353  360  387  413  420  425 
42  354  359  369  393  420  427  432 
FAQ
How do I calculate fundal height?
To calculate the median symphysis fundal height (SFH) use the formula:
Median SFH (cm) = 5.1333 + (0.1058 × GA²)  (0.02312 × GA²) × ln(GA)
,
where GA
is the gestational age in weeks.
Can fundal height predict birth weight?
Fundal height can predict the birth weight of your baby — however, this method can only be used after 3336 weeks of the pregnancy, when your baby is in the vertex position (with their head down).
In order to calculate the estimated birth weight using the fundal height we need to use the Johnson's formula:
Fetal weight = (SFH  Weight  Vertex) × 155
When to start measuring fundal height?
You may start measuring your fundal height during the 1214th week of the pregnancy — that's when the fundus of the uterus starts to be easily palpable above your pubic bone.