Kidney function · For patients and doctors
Enter your creatinine, and your urine albumin if you have it. You get your kidney number (eGFR), your stage, how often to check it, and what to do next. Doctors get the full clinical view: every equation, the KDIGO grid, kidney failure risk, the trend and medicine doses.
A calculator, not a diagnosis. One abnormal result does not mean kidney disease: it has to last at least three months. Take the result to your doctor. Nothing you enter leaves this page.
Add past results with their dates. Use the same unit as above. Age at each date is worked out for you.
| Equation | Result | Use |
|---|
Generic names. Label thresholds use eGFR unless marked CrCl (Cockcroft-Gault). Rows needing a change or caution at this level are highlighted. Check the current label before prescribing.
| Medicine | At this patient's level | Rule |
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In 412 Indian adults with measured GFR (Yadav et al., Kidney International Reports 2024), creatinine-based CKD-EPI 2021 overestimated GFR by about 19 mL/min/1.73m² on average, and only 41% of estimates were within 30% of measured GFR. Cystatin C alone was within 30% in 61%, and the combined equation in 55%. Lower muscle mass and vegetarian diets are the likely reasons. When a decision turns on the number (starting or stopping a medicine, referral, a borderline stage), a cystatin C level is worth ordering.
eGFR (estimated glomerular filtration rate) is how much blood your kidneys clean each minute, estimated from a blood test. A healthy young adult is usually above 90. It falls slowly with age. It is an estimate: muscle, diet and illness move creatinine, which is why a second marker, cystatin C, is sometimes added.
The albumin-creatinine ratio (ACR) looks for albumin leaking into the urine. In diabetes it is often the first sign of kidney damage, years before eGFR falls, and it is the part that treatment can bring down. Below 30 mg/g (3 mg/mmol) is normal. 30 to 299 is moderately increased. 300 or more is severely increased. Because exercise, fever, a urine infection or very high sugars can raise it for a day, a raised result is repeated, ideally on an early-morning sample.
Chronic kidney disease means an eGFR below 60, or signs of kidney damage such as albumin in the urine, lasting more than three months. A single low value after a fever, dehydration or a new medicine may recover. Repeat it before drawing conclusions.
Kidney function falls slowly with age. These are the average eGFR values in healthy adults. They are averages, not cut-offs: a lower value can still be normal for an older person if the urine albumin is normal and the number is not falling.
| Age | Average eGFR (mL/min/1.73m²) |
|---|---|
| 20 to 29 years | 116 |
| 30 to 39 years | 107 |
| 40 to 49 years | 99 |
| 50 to 59 years | 93 |
| 60 to 69 years | 85 |
| 70 years and above | 75 |
Source: National Kidney Foundation.
The stage comes from the eGFR. The urine albumin (A1, A2, A3) is added to it to judge risk, which is what the chart in the calculator shows.
| Stage | eGFR | What it means |
|---|---|---|
| G1 | 90 or more | Normal or high. CKD only if there is kidney damage, such as albumin in the urine. |
| G2 | 60 to 89 | Mildly reduced. CKD only if there is kidney damage. |
| G3a | 45 to 59 | Mildly to moderately reduced. |
| G3b | 30 to 44 | Moderately to severely reduced. |
| G4 | 15 to 29 | Severely reduced. A kidney specialist should be involved. |
| G5 | Below 15 | Kidney failure. |
Stages as defined by KDIGO 2024. A stage needs the result to last at least three months.
In a young adult, 90 or more is normal. eGFR falls slowly with age, so 60 to 89 is common in older people. On its own, 60 to 89 is not kidney disease. It counts as chronic kidney disease (CKD) only if there is also a sign of kidney damage, such as albumin in the urine, for at least three months.
An eGFR of 55 is stage G3a (45 to 59): mildly to moderately reduced kidney function. If it stays below 60 for three months or more, that is CKD. Repeat the test, get a urine albumin-creatinine ratio (ACR) and see your doctor. Many people at this stage stay stable for years with good control of sugar and blood pressure and the right medicines.
It depends on age and sex. With the CKD-EPI 2021 equation, a creatinine of 1.4 mg/dL gives an eGFR of about 58 in a 60-year-old man (stage G3a) and about 43 in a 60-year-old woman (stage G3b). This is why the same creatinine can mean different things for different people.
Yes. Most Indian labs report creatinine in mg/dL, and the calculator takes mg/dL or µmol/L. To change µmol/L to mg/dL, divide by 88.4.
Less than we would like. In a 2024 study of 412 Indian adults whose kidney function was measured directly, creatinine-based eGFR read higher than the true value by about 19 on average. Cystatin C was more accurate. When a decision depends on the number, ask your doctor about a cystatin C test. The calculator uses it if you have it.
A low value caused by dehydration, fever or a new medicine often recovers, which is why one result is not a diagnosis. In established CKD, the aim is to slow the fall: control of blood sugar and blood pressure, avoiding painkillers such as NSAIDs, and kidney-protective medicines your doctor may add, such as an SGLT2 inhibitor or an ACE inhibitor or ARB.
For adults, the race-free CKD-EPI 2021 creatinine equation, which most labs use and KDIGO 2024 recommends. With cystatin C it also gives the combined creatinine-cystatin C result. Under 18, it uses the CKiD U25 equation, which needs height. Doctors can see every equation side by side.
Found an error? Write to info@caspianhealthcare.in. Kidney diet guidance for clinicians: diet in CKD with diabetes.