What Is a Normal GFR at Your Age?

1. What does your eGFR number mean?

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. If you want the test itself rather than the age comparison, our guide to the eGFR blood test walks through how it is taken and what each stage means. If it is the creatinine line that came back flagged rather than the eGFR, our guide to high creatinine levels reads that number value by value. And if you want all five figures on the report read together, U&E results explained takes them one at a time. The urea line climbs with age in much the same way, which urea levels by age sets out decade by decade. A urea above the range has its own explanation in high urea levels.

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.

Here is what each band means in plain words. Find your number, then read the age section below for the context that goes with it.

What does an eGFR of 78, 71 or 54 mean?

Most people arrive here with one number in mind. Below is that number, read one value at a time. Glomerular filtration rate is the full name, so a result written as “GFR 71” and one written as “eGFR 71” mean the same thing.

One caveat on the whole table. A stage label is not a diagnosis. Chronic kidney disease needs an eGFR under 60 twice, at least 90 days apart, plus other evidence of kidney damage such as protein in your urine. A qualified clinician reads your number with the rest of your results. If yours has landed under that line, our guide to low eGFR levels reads the bands one at a time.

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.

That slow decline is one reason the NHS tells older people not to take potassium supplements without a doctor. Ageing kidneys clear potassium less readily.

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.

3. What is a normal GFR for age 80?

At 80, the middle GFR reading is 66 for men and 63 for women. Nine in ten healthy 80-year-olds sit somewhere between 46 and 84. So a number in the 60s is ordinary at that age, even though your lab still prints 90 next to it.

That figure comes from the largest dataset we have on healthy older kidneys. A 2025 study in Kidney International screened 2.57 million people across seven European countries and kept the 1.54 million with no kidney disease. Ages ran to 105.

Compare that with 20-year-old men in the same study. Their middle reading was 99, and the lowest 1 in 20 was 78. A healthy 80-year-old filters at roughly two thirds the rate of a healthy 20-year-old.

So what about 60, 70 and 75?

Use the table in the section above. The German data puts the middle reading near 89 at 65 and near 80 to 85 at 75. Those are population medians, not a range your lab measures you against.

Two cautions before you use any of this. The 2025 study used a newer formula called EKFC. UK labs use CKD-EPI, and the two do not match exactly. And none of these numbers is a target. They tell you what is typical, not what is right for you.

The second caution matters more at 80 than at any other age. Age-adapted thresholds are actively debated among kidney specialists, and UK practice has not moved. A qualified clinician reads your number alongside your urine test, your trend and your other risk factors.

4. 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. Plenty of 70-year-olds sit above 90.

What the age data gives you is context for a mildly low result. An eGFR of 78 at 62 sits near the population median. That is context, not an all-clear. A qualified clinician reads your number alongside your trend, your urine test and your risk factors.

5. 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.

6. 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. NICE advises no meat in the 12 hours before an eGFR blood 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.

7. 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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