eGFR calculator
Enter the creatinine from your blood test, your age and sex. The calculator works out eGFR with EKFC, the equation Norwegian laboratories adopted in 2026, and explains what the number means.
Fill in creatinine, age and sex to see the result.
An estimate, not a diagnosis. What you type stays in your browser and is not sent to us. A doctor always reads eGFR together with the urine test, blood pressure and the trend over time.
What is eGFR?
eGFR stands for estimated glomerular filtration rate. It is an estimate of how much blood the kidneys clean each minute, worked out from creatinine in the blood, age and sex. The higher the number, the better the kidneys filter. In young adults eGFR is usually above 90, and it falls a little each year after 40.
Why does the calculator show two numbers?
In 2026 Norwegian laboratories moved from the CKD-EPI equation to EKFC, which is more accurate in young adults and older people. EKFC often gives a slightly lower number than CKD-EPI without the kidneys having got worse. If you have older results, it helps to see both. Compare numbers calculated with the same equation where you can.
What can make eGFR wrong?
Because eGFR is calculated from creatinine, the number is misleading when creatinine is high or low for reasons other than the kidneys. A lot of muscle, creatine supplements and a large meat meal before the test can give too low an eGFR. Little muscle mass can give too high an eGFR. The calculator is not suitable for children, during pregnancy or in acute illness.
eGFR categories
G1
- eGFR
- 90 or more
- Meaning
- Normal
G2
- eGFR
- 60 to 89
- Meaning
- Mildly decreased
G3a
- eGFR
- 45 to 59
- Meaning
- Mildly to moderately decreased
G3b
- eGFR
- 30 to 44
- Meaning
- Moderately to severely decreased
G4
- eGFR
- 15 to 29
- Meaning
- Severely decreased
G5
- eGFR
- Below 15
- Meaning
- Kidney failure
Questions about eGFR
What is a normal eGFR?
In young adults eGFR is usually above 90. It falls by about one unit a year after the age of 40, so an eGFR between 60 and 89 is common in older people and does not mean kidney disease on its own.
What does an eGFR below 60 mean?
An eGFR below 60 in two tests at least three months apart means chronic kidney disease, at any age. A single low value is not enough, because the number can drop temporarily with dehydration, illness or some medicines.
Which equation does the calculator use?
The main number uses EKFC (Pottel and colleagues 2021), which Norwegian laboratories use. For comparison it shows CKD-EPI 2021, the equation many older results were calculated with.
Can I trust the result?
It is the same calculation the laboratory makes, but it is an estimate and not a diagnosis. The laboratory result and your doctor's assessment always come first.
Sources
- Development and validation of a modified full age spectrum creatinine-based equation to estimate glomerular filtration rate (EKFC). Pottel H. et al., Annals of Internal Medicine 2021
- New creatinine and cystatin C based equations to estimate GFR without race (CKD-EPI 2021). Inker L.A. et al., New England Journal of Medicine 2021
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. KDIGO
Read more
Follow your numbers over time
In the Nyrami app you keep eGFR, creatinine, albumin and blood pressure in one place and see the trend explained in words. Free on iPhone and Android.