# Pediatric GFR Calculator - Glomerular Filtration Rate

This pediatric GFR calculator is a version of our GFR calculator that is targeted for patients who are 18 years old or younger. There is a substantial difference in the way that this indicator is calculated for adults and children; read on to discover what it is and become familiar with the proper formulas.

## What is GFR?

Glomerular filtration rate, or GFR for short, is a test for determining the risk of kidney disease. It can be calculated from your blood test results.

The unit of GFR is mL/min/1.73m². The value 1.73m² is the standarized body area. Because the body area is different for kids at various ages, the equations listed below take into consideration the height factor.

## How to calculate GFR

According to the National Kidney Foundation, there are three main qays to estimate the GFR of children. Our pediatric GFR calculator uses all of them, so that you can compare all results and see whether all of them are in the normal range.

- Creatinine-based “Bedside Schwartz” equation (2009)

This is the standard - and the best method - for estimating GFR in children aged 1-18. Since it was updated in 2009, it no longer returns overestimated results.

`GFR = 41.3 * (height / Scr)`

where:

- Height is expressed in meters;
- SCr is the level of standarized serum creatinine in mg/dL.

- Cystatin C-based equation (2012)

This formula uses the level of serum cystatin C instead of the creatinine indicator. It is a good confirmatory test, as well as a recommended one if the levels of creatinine are fluctuating.

`eGFR = 70.69 * Scys^(-0.931)`

where:

- Scys is the level of standarized serum cystatin C in mg/L.

- Creatinine-Cystatin C-based CKiD equation (2012)

This test uses both creatinine and cystatin C indicators. It is a good confirmatory test, too.

`GFR = 39.8 * (height/Scr)^0.456 * (1.8/Scys)^0.418 * (30/BUN)^0.079 * a * (height/1.4)^0.179`

where:

- Height is expressed in meters;
- a is a coefficient dependent on sex: 1 for females, 1.076 for males;
- BUN is the level of blood urea nitrogen in mg/dL;
- Scys is the level of standarized serum cystatin C in mg/L;
- SCr is the level of standarized serum creatinine in mg/dL.

## What levels of GFR are alarming?

The list below shows the typical values of GFR on different stages of kidney malfunction.

- No kidney damage or mild kidney damage with normal kidney function: 90 or above
- Kidney damage with mild loss of kidney function: 89 to 60
- Mild to moderate loss of kidney function: 59 to 44
- Moderate to severe loss of kidney function: 44 to 30
- Severe loss of kidney function: 29 to 15
- Kidney failure: Less than 15