Kidney and organ health
Normal eGFR by Age: Is Your Kidney Number Fine for Your Age?
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed August 20268 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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UK labs use one eGFR threshold at every age: above 90 is normal, and below 60 needs review. But average eGFR does fall with age, by roughly 1 mL/min a year after 40. So 75 is common at 70 and worth a closer look at 30. Trend beats any single reading.
Not sure which markers you need? Build your test →You open your results and one number is flagged. Your eGFR reads 78, and the range next to it starts at 90. You are 62. The obvious question follows: is 78 a problem, or is it just what 62 looks like?
This guide answers that. It covers what a normal eGFR is, how much the average drops with age, and why the honest answer to “what should mine be at my age?” is more useful than the age charts you will find elsewhere.
1. What counts as a normal eGFR?
Above 90 is the number to know. eGFR stands for estimated glomerular filtration rate. It is an estimate of how many millilitres of blood your kidneys filter each minute. The NHS sets the bar plainly.
“Healthy kidneys should be able to filter more than 90ml/min.”
— NHS, Chronic kidney disease: Diagnosis
Your eGFR is not measured directly. A lab measures creatinine, a waste product from muscle, then a formula converts it using your age, sex and body size. Age is already inside the sum. That single fact explains most of the confusion below.
The UK Kidney Association groups results into stages: G1 is above 90, G2 is 60 to 89, G3a is 45 to 59, G3b is 30 to 44, G4 is 15 to 29 and G5 is below 15.
2. Does eGFR fall with age?
Yes, and this is the part most result letters skip. Kidney filtering slows gradually across adult life, in people with no kidney disease at all. A 2024 systematic review in BMJ Open put the normal rate of decline at between 0.37 and 1.07 mL/min/1.73m² a year in healthier groups.
The German Gutenberg Health Study measured 12,381 adults and found a median loss of about 1 mL/min a year. Median eGFR ran near 110 at age 35 and near 80 to 85 at age 75.
| Age | Typical median eGFR | CKD stage label |
|---|---|---|
| 35 | around 110 | G1 |
| 45 | around 103 | G1 |
| 55 | around 96 | G1 |
| 65 | around 89 | G2 |
| 75 | around 80 to 85 | G2 |
3. Is there an official eGFR-by-age chart in the UK?
No. This is the honest answer, and it matters more than any chart. UK labs report one threshold at every age. A 25-year-old and an 80-year-old are both measured against 90 and 60. The NHS publishes no age-banded normal range for eGFR.
So the age charts on other sites are averages dressed up as targets. An average tells you what is common. It does not tell you what is healthy for you. Plenty of 70-year-olds sit above 90.
What the age data really gives you is context for a mildly low result. If your eGFR is 78 at 62, you are close to the population median for your age. That is reassuring, though it is context and not an all-clear. A qualified clinician reads your number alongside your trend, your urine test and your risk factors.
4. When does a lower eGFR actually matter?
One reading is never the answer. Chronic kidney disease is defined by changes lasting more than three months, not by a single result. The UK eCKD guide requires an eGFR below 60 on at least two occasions, 90 days apart.
An eGFR between 60 and 89 on its own is not enough for a diagnosis either. It is labelled G2 only when there is other evidence of kidney damage, such as protein in the urine. This is set out in the NICE chronic kidney disease guideline (NG203).
These patterns are worth a GP conversation whatever your age:
- An eGFR that keeps sliding across repeated tests.
- A result below 60 that is confirmed on a second test.
- Protein or blood found in your urine.
- Diabetes, high blood pressure, or regular anti-inflammatory use.
- Swelling, unusual tiredness, or a change in how much you pass urine.
5. What can make your eGFR look worse than it is?
Because eGFR is calculated from creatinine, anything that raises creatinine drags the estimate down. None of these harm the kidney. They just move the number.
- Muscle mass. More muscle means more creatinine at baseline.
- Creatine supplements. See does creatine raise creatinine for the full mechanism.
- A big protein meal or a hard workout in the day before your test.
- Dehydration on the morning of the sample.
There is one way around all of this. Cystatin C is a filtration marker that muscle and supplements do not sway. It is a specialist add-on rather than a standard line item, and it is not part of Helvy's current panels. It is a sensible marker to ask about if a creatinine-based result looks out of character.
6. Which blood test shows your eGFR
The markers you want are creatinine, urea and eGFR. One reading tells you where you sit today. Two readings, months apart, tell you the thing that actually matters: the direction.
Helvy's Thyroid & Vital Organs panel (£159) reports all three, alongside thyroid, liver and full cholesterol markers. It is a home finger-prick test, processed by UKAS-accredited UK labs. If you want a wider baseline first, our full blood count guide covers the other half of a routine picture.
To assemble your own marker list, the build-my-test tool walks you through it.
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Know your kidney trend, not just today's number
Helvy's home blood tests report creatinine, urea and eGFR with plain-English context, so a mildly low result never sparks a needless panic. Samples are processed by UKAS-accredited UK labs.
Frequently asked questions
What is a normal eGFR by age in the UK?
UK labs use one threshold at every age. Above 90 is normal and below 60 needs review. Average eGFR does fall with age, from around 110 at 35 to around 80 to 85 at 75 in a large German population study. Those are averages, not age-specific normal ranges.
Is an eGFR of 75 normal at 70?
It is common at that age. An eGFR of 60 to 89 is labelled G2, and it only counts as chronic kidney disease when there is other evidence of kidney damage, such as protein in the urine. The same 75 in a 30-year-old would usually prompt a closer look. Ask a qualified clinician to read yours in context.
How fast does eGFR decline with age?
A 2024 systematic review in BMJ Open put normal decline at between 0.37 and 1.07 mL/min/1.73m² a year in healthier groups. The Gutenberg Health Study found a median loss of about 1 mL/min a year. Rates vary a lot between people, which is why your own trend beats any average.
Does eGFR get adjusted for age on my results?
Partly. Your age is already used in the formula that turns creatinine into eGFR. But the reference range printed beside it is not age-banded. So the number is age-aware and the threshold is not.
Should I worry about one low eGFR reading?
One reading rarely means much on its own. Chronic kidney disease needs an eGFR below 60 on at least two occasions, 90 days apart. Dehydration, a hard workout, a big protein meal or creatine can all depress a single result. Repeat the test before you draw a conclusion.
Can you raise your eGFR?
A number depressed by dehydration, creatine or a hard session usually returns to baseline once those pass. Age-related decline is not reversible. Managing blood pressure and blood sugar is the evidence-backed way to protect kidney function over time, and that is a conversation for your GP.
Related guides
Kidney Function Test UK
Creatinine, eGFR, urea and electrolytes explained, with CKD staging.
Creatinine Blood Test UK
Why a high creatinine is usually muscle, protein or a supplement.
Cystatin C Blood Test UK
The filtration marker that muscle mass and creatine don't skew.
Does Creatine Raise Creatinine?
How a supplement can push a healthy eGFR below the normal line.
Blood Test Reference Ranges UK
Why 'normal' on a lab report is a population range, not a target.
Thyroid & Vital Organs Test
Kidney, liver, thyroid and cholesterol markers in one home test.