Estimate your kidney filtration rate (eGFR) from a recent creatinine blood test. Diabetes is the leading cause of chronic kidney disease — annual eGFR is part of the standard NICE NG28 review. This calculator uses the 2021 CKD-EPI equation (race-free), the version recommended by NICE, NHS England, and the National Kidney Foundation.
eGFR Calculator (CKD-EPI 2021, race-free)
What eGFR measures
eGFR (estimated glomerular filtration rate) is the best single number for kidney function — how much blood the kidneys can filter per minute. The number is “estimated” because it’s calculated from a blood test (creatinine), age, and sex rather than measured directly. The 2021 CKD-EPI equation is the version that NICE, NHS England, and the National Kidney Foundation now recommend; the older “MDRD” equation has been retired.
CKD stages by eGFR
| Stage | eGFR (ml/min/1.73m²) | Description |
|---|---|---|
| G1 | ≥ 90 | Normal or high |
| G2 | 60 – 89 | Mildly decreased |
| G3a | 45 – 59 | Mildly to moderately decreased |
| G3b | 30 – 44 | Moderately to severely decreased |
| G4 | 15 – 29 | Severely decreased |
| G5 | < 15 | Kidney failure |
Why diabetes makes kidney monitoring critical
Diabetes is the single biggest cause of chronic kidney disease worldwide. Damage progresses silently for years before symptoms appear. NICE NG28 recommends both eGFR and a urine albumin-to-creatinine ratio (uACR) at least once a year for everyone with diabetes — uACR picks up albumin leak in the urine before eGFR falls.
The combination matters: a person with eGFR 75 and uACR 5 has CKD even though their eGFR alone looks fine. A person with eGFR 75 and uACR <3 doesn’t.
What slows progression
- Tight blood pressure control with an ACE inhibitor or ARB if there’s albuminuria.
- SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin) — now standard for diabetic CKD with eGFR ≥20 in many guidelines.
- Finerenone — non-steroidal mineralocorticoid receptor antagonist for type 2 diabetes with CKD.
- GLP-1 receptor agonists — show kidney benefit in cardiovascular outcome trials.
- Tight glycaemic control — particularly important early.
- Avoid NSAIDs for chronic pain in CKD where possible.
FAQ
Why doesn’t this calculator ask about race?
The 2021 CKD-EPI equation removed race as a variable. The previous equation used a Black-race coefficient that the National Kidney Foundation and American Society of Nephrology Task Force concluded was inappropriate. The race-free equation is now used by the NHS, NICE, KDIGO, and most US labs.
What’s a normal eGFR?
Above 90 ml/min/1.73m² is “normal.” eGFR also drops naturally with age — losing about 1 ml/min/1.73m² per year after age 30. An eGFR of 75 in a 70-year-old is not the same clinical concern as 75 in a 35-year-old.
Can eGFR improve?
Yes — particularly when caught early. SGLT2 inhibitors initially cause a small drop in eGFR (3–5 ml/min) within weeks, then stabilise the long-term decline. Other reversible factors include dehydration, untreated high blood pressure, NSAIDs, and decompensated diabetes.
Related
- Diabetes Complications: kidney, heart, eye, foot
- The UACR Test: your best defence against kidney disease
- SGLT2 Inhibitors for Kidney Protection
- All diabetes calculators
References: Inker LA, Eneanya ND, Coresh J, et al. New creatinine- and cystatin C–based equations to estimate GFR without race. NEJM 2021;385:1737-1749. NICE NG203 (CKD). NICE NG28. KDIGO 2024 CKD guideline. Reviewed: May 2026.