Kidney and organ health
What Is a Normal eGFR? Your Kidney Number, by Age
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed July 20267 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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eGFR (estimated glomerular filtration rate) shows how fast your kidneys filter blood. It is calculated from your creatinine result, age and sex. 90 or above is normal. A result below 60 on two tests at least three months apart may point to reduced kidney function, and is worth discussing with your GP.
Find the test that fits your symptoms →As of July 2026. This guide uses NHS wording, NICE guideline NG203 and current UK laboratory practice. Every figure is cited and linked.
eGFR is the number most people notice first on a kidney result. It often arrives with no explanation, sometimes flagged in red. So what counts as normal, why does it fall as you get older, and when does a low number actually matter?
1. What is an eGFR blood test?
eGFR stands for estimated glomerular filtration rate. Your glomeruli are the tiny filters inside your kidneys. eGFR estimates how many millilitres of blood they clean per minute. The higher the number, the better your kidneys are filtering.
It is not measured directly. The lab measures creatinine, a waste product from normal muscle use. A formula then combines your creatinine with your age and sex to estimate your filtration rate. The NHS sets the healthy benchmark plainly.
“Healthy kidneys should be able to filter more than 90ml/min.”
— NHS, Chronic kidney disease: diagnosis
eGFR usually appears alongside urea and creatinine on a kidney panel, and it is a standard part of a general health MOT. Many people first meet it next to a full blood count in routine GP bloods. For the wider kidney picture, see our kidney function test guide.
2. What is a normal eGFR, and does age matter?
There is no separate NHS range for each age. An eGFR of 90 or above counts as normal at any age. A healthy young adult typically filters at 100 to 120 mL/min/1.73m². From around age 40, eGFR drifts down by roughly 1 mL/min each year, according to longitudinal data in the BMJ. That is normal ageing, not disease.
This is why context matters more than the raw number. An eGFR of 75 in a 70-year-old is unremarkable. The same 75 in a 25-year-old is a prompt to recheck. Doctors read your result against your age, your history and, most importantly, your trend over time. For the typical median at each decade, see eGFR levels by age.
UK practice groups eGFR into categories, set out in NICE guideline NG203:
| Category | eGFR (mL/min/1.73m²) | What it describes |
|---|---|---|
| G1 | 90 or above | Normal filtration |
| G2 | 60–89 | Mildly reduced; common with age |
| G3a | 45–59 | Mild to moderate reduction |
| G3b | 30–44 | Moderate to severe reduction |
| G4 | 15–29 | Severe reduction |
| G5 | Below 15 | Kidney failure |
One important detail: a result between 60 and 89 on its own is not a diagnosis of anything. For most people it simply reflects age, or a temporary dip. It becomes meaningful only alongside other signs of kidney trouble, or a clear downward trend.
You may also notice your lab caps the number, reporting anything above 90 as simply “>90”. That is deliberate. The formula loses precision at the top of the range, so there is no useful difference between a 95 and a 110. Do not read a capped result as a decline.
3. What does a low eGFR mean?
Under NICE NG203, chronic kidney disease is only considered when eGFR stays below 60 on tests at least three months apart, or there are other markers of kidney damage. One low reading is never the whole story, because several everyday things can drag a single result down:
- Dehydration. Less fluid on board concentrates creatinine and lowers the estimate.
- Muscle mass. More muscle means more creatinine. Muscular people can show a lower eGFR with healthy kidneys.
- Creatine supplements. Creatine raises creatinine and can falsely depress eGFR. Our creatine and creatinine guide covers this in detail.
- A large meat meal or hard training shortly before the test.
A persistently low result matters because kidney trouble is usually silent. Kidney Research UK estimates around 7.2 million people in the UK have chronic kidney disease, and that 30 to 50% of cases in high-income countries are not picked up early enough for timely intervention (June 2026 report).
There is also a second way to estimate filtration. If muscle mass or supplements make your creatinine unreliable, labs can calculate eGFR from cystatin C instead. It is a protein that does not depend on muscle, so it gives a cleaner read in very muscular or very slight people.
The trend is what clinicians watch. NICE treats a sustained drop of more than 5 mL/min/1.73m² within a year as significant. If your eGFR is below 60, or falling fast, take the result to your GP. If it sits in the 60s and you feel well, a repeat test after a few months is the usual next step.
4. How to check your eGFR at home
You do not need to wait for a GP appointment to see your number. Helvy’s Thyroid & Vital Organs panel (£159) measures eGFR, creatinine and urea from a home finger-prick sample, read alongside your thyroid and liver markers. The General Energy & Wellness panel (£149) includes urea and creatinine as part of a broader check.
Because eGFR is an estimate that moves with hydration and training, one home reading is a starting point, not a verdict. The value is in the trend: the same test, repeated over months, shows whether your number is stable or drifting. For most people, checking once or twice a year is plenty.
Not sure which markers you need? The build-my-test tool matches you to the right panel. Results arrive in about five working days from UKAS-accredited UK laboratories, with each marker explained.
READY TO TEST?
See your eGFR in context
Helvy’s home blood tests read eGFR, creatinine and urea with clear context, so you can see how your kidneys are filtering and track it over time. Results in about 5 working days from UKAS-accredited UK laboratories.
Frequently asked questions
What is a normal eGFR for my age?
The NHS uses one benchmark for all ages: 90 or above is normal. But eGFR naturally falls by about 1 mL/min a year from around age 40, so results in the 60s and 70s are common in older adults without any kidney problem. Doctors read the number against your age and your trend, not in isolation.
Can my eGFR go back up?
A single low reading often improves on retest, because dehydration, hard training, a big meat meal or creatine supplements can all lower one result. A long-term decline is a different matter and needs a qualified clinician’s input. This is general information, not medical advice.
Do I need to fast for an eGFR blood test?
No. eGFR is calculated from creatinine, which does not require fasting. Avoid heavy exercise and large meat meals the day before, and drink normally, so the reading reflects your usual baseline.
Why is my eGFR low if I feel fine?
Early kidney changes rarely cause symptoms, which is why the number can surprise people who feel well. It can also read low for harmless reasons, such as high muscle mass. A repeat test three months later is the standard way to tell a blip from a trend. If it stays below 60, speak to your GP.
Related guides
Kidney Function Test UK
The full results guide: creatinine, eGFR, urea and CKD stages.
Creatinine Blood Test UK
What a high creatinine really means, and when it matters.
Does Creatine Raise Creatinine?
Why supplements can make healthy kidneys look impaired.
Urea and Electrolytes (U&E)
Sodium, potassium, urea and creatinine explained.
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