eGFR 15: What It Means (CKD Stage G4)
An eGFR of 15 mL/min/1.73m² is KDIGO category G4 (15 to 29). This page explains what it means, the creatinine behind it, and what to ask next.
Medically reviewed by Dr. Rishi Kumar Kafle, MBBS, MD, FASN. Last reviewed October 2026.
An eGFR of 15 mL/min/1.73m² falls in KDIGO category G4 (15 to 29), which means severely decreased filtration. At age 50 it matches a creatinine of about 4.52 mg/dL in a man and 3.55 mg/dL in a woman. This is below 30, the level at which KDIGO advises sharing care with a kidney specialist (nephrologist).
Where 15 Sits Within G4
An eGFR of 15 sits exactly on the lower edge of G4: a result of 14 would be G5. It is 15 points below the G3b line at 30. The KDIGO categories run from G1 to G5; G4 is explained in more depth on the CKD stage 4 page.
G4 is severely decreased filtration. KDIGO advises sharing care with a kidney specialist (nephrologist) once eGFR is below 30, and this is usually when planning for future treatment options begins, well ahead of any need.
What Creatinine Gives an eGFR of 15?
The creatinine behind an eGFR of 15 comes from solving the race-free CKD-EPI 2021 equation backwards, by age and sex:
| Age | Man | Woman |
|---|---|---|
| 30 | 5.01 mg/dL (443 µmol/L) | 3.94 mg/dL (348 µmol/L) |
| 40 | 4.76 mg/dL (421 µmol/L) | 3.74 mg/dL (331 µmol/L) |
| 50 | 4.52 mg/dL (400 µmol/L) | 3.55 mg/dL (314 µmol/L) |
| 60 | 4.29 mg/dL (379 µmol/L) | 3.37 mg/dL (298 µmol/L) |
| 70 | 4.08 mg/dL (360 µmol/L) | 3.20 mg/dL (283 µmol/L) |
| 85 | 3.77 mg/dL (333 µmol/L) | 2.96 mg/dL (262 µmol/L) |
A 30-year-old man reaches 15 at 5.01 mg/dL, while an 85-year-old woman reaches it at 2.96 mg/dL. The older the person, the lower the creatinine behind the same eGFR. Nearby creatinine guides: creatinine 5.0 mg/dL (442 µmol/L).
eGFR 15 in Absolute mL/min
eGFR is indexed to a body surface area (BSA) of 1.73m². To compare it with a creatinine clearance, or for a very small or large adult, it can be de-indexed with eGFR × BSA ÷ 1.73. For an eGFR of 15, the absolute values are:
| Example adult | BSA (m²) | Absolute GFR (mL/min) |
|---|---|---|
| Man, 40, 178 cm, 80 kg | 1.99 | 17 |
| Woman, 65, 163 cm, 62 kg | 1.67 | 15 |
| Woman, 82, 157 cm, 48 kg | 1.45 | 13 |
| Man, 55, 175 cm, 118 kg | 2.40 | 21 |
What Changes at an eGFR of 15
15 sits exactly on the 15 line, so a result of 14 would cross it. Below 15, the result is in the kidney failure range (G5). It is already below 60 and 30.
9 of the 9 medicines in our registry whose labels use eGFR have a rule in force at 15. No eGFR-based rule in the registry starts between 20 and 15.
| Medicine | At eGFR 15 | Next change if eGFR falls |
|---|---|---|
| Metformin | contraindicated | none lower in the registry |
| Sitagliptin | dose lowered to 25 mg | none lower in the registry |
| Saxagliptin | dose lowered to 2.5 mg | none lower in the registry |
| Dapagliflozin | glucose-lowering effect limited; below the floor of 25 the registry gives for its kidney disease use | none lower in the registry |
| Empagliflozin | glucose-lowering effect limited; other uses follow the indication | none lower in the registry |
| Canagliflozin | use limited; depends on the indication | none lower in the registry |
| Spironolactone | avoid | none lower in the registry |
| Hydrochlorothiazide | ineffective; the registry suggests a loop diuretic instead | none lower in the registry |
| Glyburide | avoid (CKD stage 3 to 5) | none lower in the registry |
These rows restate our renal dosing registry, which summarises the drug labels. Check the current label and the indication; the prescriber makes the dose decision.
Drug Dosing Cutoffs at eGFR 15
8 drugs in our renal dosing registry have a label cutoff at 15.
Labels That Use Creatinine Clearance
These labels use Cockcroft-Gault creatinine clearance in mL/min, not eGFR. An eGFR of 15 does not mean a clearance of 15 mL/min, so calculate CrCl before applying them.
- Dabigatran: CrCl 15 to 30
- Edoxaban: CrCl 15 to 50; below 15
- Gabapentin: CrCl below 15
- Imipenem-Cilastatin: CrCl below 15
- Plazomicin: CrCl 15 to below 90
- Rivaroxaban: CrCl 15 to 50; below 15
- Tenofovir DF: CrCl below 15
- Trimethoprim-Sulfamethoxazole: CrCl 15 to 30; below 15
The nearest other cutoffs are up at 20 (Dofetilide, Levofloxacin, Ofloxacin) and down at 10 (16 drugs). Always confirm the current label, and leave the dose decision to the prescriber.
How a Result of 15 Is Confirmed
A result of 15 is confirmed by repeat testing over time, because one eGFR is a snapshot that can dip with dehydration or illness. Chronic kidney disease is diagnosed only when a low result, or kidney damage, lasts more than three months. Repeat testing, a urine albumin-to-creatinine ratio and, where muscle mass misleads, cystatin C confirm it.
When to Talk to Your Clinician
An eGFR of 15 should be reviewed promptly, usually with a kidney specialist, even if you feel well. Seek timely advice for swelling, a marked drop in urine output or new breathlessness, and have kidney function rechecked before and after any scan that uses contrast dye.
Nearby eGFR Results
Or browse all eGFR results. For drug dosing, your clinician may use a creatinine clearance rather than eGFR (see CrCl vs eGFR).