This chronic kidney disease calculator follows the CKD- EPI formula to compute the GFR value and indicate the condition of the kidneys based on serum creatinine. You can read more on this formula and its application below the form.


How does this chronic kidney disease calculator work?

This is a health tool that uses the CKD-EPI formula (Chronic kidney disease epidemiology collaboration) to estimate the glomerular filtration rate (GFR) in a modern way.

The chronic kidney disease calculator requires you to input the serum creatinine level, either in mg/dL or umol/L, the age and select the gender and race in order to customize the formula and reveal the result.

The CKD-EPI formula

This is a new formula developed to address the issues in the MDRD formula (Modification of Diet in Renal Disease) and to improve GFR estimation methods.

This is basically a way to assess kidney function. This formula, to be used for adults over 18, brings improvement especially in cases where higher GFR values (60- 120 ml/min) were often underestimated.

GFR = 141 X min(Cr/κ,1)α X (max(Cr/κ,1)^-1.209) X (0.993^Age) X 1.018 [if female] X 1.159 [if black]


■ Cr- is serum creatinine in mg/dL;

■ k equals 0.7 for females, 0.9 for males;

■ α is –0.329 for females and –0.411 for males.

GFR levels and CKD stages

Normal filtration rate should be of 100 but GFR levels are considered normal when they go above 90mls/min/1.73m2. This is valid as long as there aren’t any other signs of chronic disease, in such case being considered stage 1. A GFR level between 60-90 is to be considered of stage 2 if there are symptoms present.

CKD means that kidneys are not functioning properly and the severity of it can vary from mild to moderate, especially in older people to progressing to kidney failure.

What it is very serious is stat people with any stage of CKD are at risk of heart disease or stroke. Diagnosing chronic kidney disease requires two measurements of creatinine and two estimations of GFR at 90 days apart.

The below table exemplifies the 5 stages of CKD.

Stage eGFR Description
1 >90 Normal kidney function:
- Some signs of kidney disease or damage like protein in urine or blood in urine, kidney inflammation.
- To be held under observation, monitoring pressure.
2 60-89 Mildly reduced kidney function:
- Some signs pointing to kidney disease, similar to stage 1.
- However, if the GFR estimation coincides with stage 2 but there are no signs of kidney damage then there is no CKD.
3A 45-59 Moderately reduced kidney function:
3B 30-44 - Signs of kidney disease.
- Possible in elderly people without specific CKD.
4 15-29 Severely reduced kidney function:
- Close to end stage renal failure.
5 <15 or on dialysis Very severe or end stage kidney failure:
- Established renal failure.


Mathew TH, Johnson DW, Jones GR. (2007) Chronic kidney disease and automatic reporting of estimated glomerular filtration rate: revised recommendations. The Medical Journal of Australia; 187 (8): 459–63

23 Mar, 2015 | 0 comments

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