eGFR 90: What It Means (GFR Category G1)
An eGFR of 90 mL/min/1.73m² is KDIGO category G1 (90 or above). 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 90 mL/min/1.73m² falls in KDIGO category G1 (90 or above), which means normal or high filtration. At age 50 it matches a creatinine of about 1.02 mg/dL in a man and 0.80 mg/dL in a woman. On its own, a G1 result is not chronic kidney disease: that also needs a marker of kidney damage, such as albumin in the urine, lasting more than three months.
Where 90 Sits Within G1
An eGFR of 90 sits exactly on the lower edge of G1: a result of 89 would be G2. G1 has no upper limit, and creatinine-based estimates are least precise in this range. The KDIGO categories run from G1 to G5; G1 is explained in more depth on the CKD stage 1 page.
G1 is normal or high filtration. On its own it is not kidney disease: KDIGO counts G1 as chronic kidney disease only when a marker of kidney damage, most often albumin in the urine, has been present for more than three months.
What Creatinine Gives an eGFR of 90?
The creatinine behind an eGFR of 90 comes from solving the race-free CKD-EPI 2021 equation backwards, by age and sex:
| Age | Man | Woman |
|---|---|---|
| 30 | 1.13 mg/dL (100 µmol/L) | 0.88 mg/dL (78 µmol/L) |
| 40 | 1.07 mg/dL (95 µmol/L) | 0.84 mg/dL (74 µmol/L) |
| 50 | 1.02 mg/dL (90 µmol/L) | 0.80 mg/dL (71 µmol/L) |
| 60 | 0.96 mg/dL (85 µmol/L) | 0.76 mg/dL (67 µmol/L) |
| 70 | 0.92 mg/dL (81 µmol/L) | 0.72 mg/dL (64 µmol/L) |
| 85 | 0.71 mg/dL (63 µmol/L) | 0.54 mg/dL (48 µmol/L) |
A 30-year-old man reaches 90 at 1.13 mg/dL, while an 85-year-old woman reaches it at 0.54 mg/dL. The older the person, the lower the creatinine behind the same eGFR.
eGFR 90 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 90, the absolute values are:
| Example adult | BSA (m²) | Absolute GFR (mL/min) |
|---|---|---|
| Man, 40, 178 cm, 80 kg | 1.99 | 103 |
| Woman, 65, 163 cm, 62 kg | 1.67 | 87 |
| Woman, 82, 157 cm, 48 kg | 1.45 | 75 |
| Man, 55, 175 cm, 118 kg | 2.40 | 125 |
What Changes at an eGFR of 90
90 is 30 points above 60, and a fall of about 34% would cross that line. Below 60, a result lasting more than three months meets the KDIGO definition of chronic kidney disease on its own.
None of the 9 medicines in our registry whose labels use eGFR has a restriction in force at 90.
| Medicine | At eGFR 90 | Next change if eGFR falls |
|---|---|---|
| Metformin | no eGFR rule in force | at 45 or lower: not to be started; the registry advises halving an existing dose |
| Sitagliptin | no eGFR rule in force | at 44 or lower: dose lowered to 50 mg |
| Saxagliptin | no eGFR rule in force | at 45 or lower: dose lowered to 2.5 mg |
| Dapagliflozin | no eGFR rule in force | at 44 or lower: glucose-lowering effect limited |
| Empagliflozin | no eGFR rule in force | at 29 or lower: glucose-lowering effect limited; other uses follow the indication |
| Canagliflozin | no eGFR rule in force | at 29 or lower: use limited; depends on the indication |
| Spironolactone | no eGFR rule in force | at 29 or lower: avoid |
| Hydrochlorothiazide | no eGFR rule in force | at 29 or lower: ineffective; the registry suggests a loop diuretic instead |
| Glyburide | no eGFR rule in force | at 59 or lower: avoid (CKD stage 3 to 5) |
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 90
1 drug in our renal dosing registry has a label cutoff at 90.
Labels That Use Creatinine Clearance
These labels use Cockcroft-Gault creatinine clearance in mL/min, not eGFR. An eGFR of 90 does not mean a clearance of 90 mL/min, so calculate CrCl before applying them.
- Plazomicin: CrCl 15 to below 90
The nearest other cutoffs are up at 95 (Edoxaban) and down at 70 (Ganciclovir, Topiramate). Always confirm the current label, and leave the dose decision to the prescriber.
How a Result of 90 Is Confirmed
A result of 90 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 90 is usually followed at routine check-ups. Ask about a urine albumin test if you have diabetes, high blood pressure or a family history of kidney disease, since damage can be present at a normal eGFR. 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).