eGFR / GFR Calculator 2026
Estimate kidney function from a serum creatinine result, using the current race-free CKD-EPI 2021 equation for adults, or the Bedside Schwartz equation for children — with your CKD stage explained.
Adult or Pediatric?
Use the Adult calculator (CKD-EPI 2021) for anyone 18 or older. Use the Pediatric calculator (Bedside Schwartz) for children and adolescents, which uses height instead of age and sex.
Adult eGFR Calculator
CKD-EPI 2021 creatinine equation (race-free)
CKD-EPI 2021 uses biological sex, not gender identity, because it reflects average muscle mass differences in the underlying validation data.
Adult Result
Estimated GFR and CKD stage
Enter creatinine, age and sex, then click Calculate My eGFR to see your estimated kidney function.
Pediatric eGFR Calculator
Bedside Schwartz equation (2009)
The Bedside Schwartz equation needs only height and creatinine — no age or sex input required.
Pediatric Result
Estimated GFR and CKD stage
Enter height and creatinine, then click Calculate Child’s eGFR to see estimated kidney function.
KDIGO CKD Stages
Standard chronic kidney disease staging by eGFR, from KDIGO clinical practice guidelines. A CKD diagnosis also generally requires reduced eGFR or markers of kidney damage to persist for at least three months.
| 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 |
eGFR Calculator FAQ
Everything people ask before estimating kidney function from a creatinine result.
eGFR, or estimated glomerular filtration rate, is an estimate of how well the kidneys filter waste from the blood, expressed in mL/min per 1.73m² of body surface area. It’s the primary measure used to detect and stage chronic kidney disease, since it’s far more practical to estimate from a routine blood test than to measure directly.
CKD-EPI 2021 is the current recommended creatinine-based equation for estimating GFR in adults, published by the CKD-EPI collaboration in 2021. Earlier versions included a coefficient for Black race, but research found this coefficient was not a reliable biological marker and could delay diagnosis and specialist referral for Black patients, so US and international guidelines moved to this race-free version.
Creatinine clearance is typically measured directly from a 24-hour urine collection and tends to slightly overestimate true GFR because creatinine is both filtered and secreted by the kidneys. eGFR equations like CKD-EPI instead estimate GFR from a single blood creatinine value plus age and sex, calibrated against a gold-standard measured GFR, and are far more convenient for routine use.
KDIGO guidelines define six eGFR-based categories: G1 (90 or above, normal or high), G2 (60-89, mildly decreased), G3a (45-59), G3b (30-44), G4 (15-29, severely decreased), and G5 (below 15, kidney failure). A CKD diagnosis generally also requires either reduced eGFR or markers of kidney damage persisting for at least three months.
The Bedside Schwartz equation (2009) is the standard method for estimating GFR in children and adolescents. It uses only height and serum creatinine, since body composition and muscle mass in children don’t scale with age the way they do in adults, making adult equations like CKD-EPI unsuitable for pediatric use.
No. A single eGFR reading can be affected by hydration, recent meals, muscle mass, medications, and lab variability, so a low result usually needs to be confirmed with a repeat test at least three months later, alongside other markers such as urine albumin. Always interpret eGFR results together with a doctor rather than relying on a single calculator output.