Explainer · updated 2026-09-09
eGFR, explained in plain English
Key facts
- Level below which chronic kidney disease is defined when it lasts more than three months: 60 mL/min/1.73m2 (CHEN 2019)
- What eGFR is: an estimate of how much blood the kidneys filter each minute, worked out from creatinine rather than measured directly; the number kidney disease is staged on (CHEN 2019)
- The formula behind the estimate: CKD-EPI, a creatinine-based formula normalised to 1.73 m2 of body surface area (CHEN 2019)
- What a high reading can mean: the kidneys are filtering faster than typical (hyperfiltration), seen in early diabetes, in pregnancy and with obesity (CHEN 2019)
- What can raise the estimate without kidney disease: a high-protein meal lifts it, and pregnancy raises it genuinely (HELAL 2012)
What it is
eGFR stands for estimated glomerular filtration rate. It is an estimate of how much blood your kidneys filter each minute, worked out from your creatinine rather than measured directly. The estimate is calculated with the CKD-EPI formula, a creatinine-based formula normalised to 1.73 m2 of body surface area. It is the number kidney disease is staged on, so it leads the kidney panel.
What the number is telling you
The estimate is worked out from your creatinine rather than measured directly, and it is the number kidney disease is staged on. Below 60 mL/min/1.73m2 for more than three months is how chronic kidney disease is defined, so a low result gets repeated first. One reading says little; time and trend matter.
What high or low can mean
High: A figure above the usual range means the kidneys are filtering faster than typical (hyperfiltration). It is seen in early diabetes, in pregnancy and with obesity. A high-protein meal lifts it too, so a single high reading in those settings is not by itself read as a kidney problem.
Low: Below 60 mL/min/1.73m2 for more than three months is how chronic kidney disease is defined, so it gets repeated first. A single low reading on its own settles nothing; it tells your doctor where to look next.
What a typical result looks like
Typical adult estimates run at or above 60 mL/min/1.73m2. That boundary comes from peer-reviewed research, the 2019 review of chronic kidney disease diagnosis and management in JAMA. The range on your own report is the one that counts.
Questions worth asking your doctor
- How was my eGFR worked out, and from which creatinine result?
- If my estimate is below 60, does it need repeating before it means anything?
- What does the trend across my previous results look like?
- Could my muscle mass, diet or medicines be pulling this number in either direction?
If a result worries you, ask your doctor.
Sources
- Chronic Kidney Disease Diagnosis and Management (2019)
- Glomerular hyperfiltration: definitions, mechanisms and clinical implications (2012)
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