Normal eGFR by Age: What Your Kidney Function Results Mean

A normal eGFR is 90 mL/min/1.73m² or higher, but eGFR naturally falls with age. Average eGFR is about 116 in your 20s, 99 in your 40s, 93 in your 50s, 85 in your 60s, and 75 at age 70 and older. An eGFR of 60 to 89 can be normal for older adults if there are no other signs of kidney damage. An eGFR below 60 for three months or longer points to chronic kidney disease. An eGFR below 15 means kidney failure.

Your doctor reads eGFR together with a urine albumin test, your age, and your health history before making a diagnosis.

What Is eGFR and What Does It Measure?

eGFR stands for estimated glomerular filtration rate. It shows how well your kidneys filter waste and extra fluid from your blood. Your kidneys contain about one million tiny filters called glomeruli. eGFR estimates how much blood passes through these filters each minute. The result is reported in milliliters per minute per 1.73 square meters of body surface, written as mL/min/1.73m².

eGFR is not measured directly. A lab calculates it from your creatinine level, a waste product made by your muscles, along with your age and sex. Most labs now use the 2021 CKD EPI equation, which no longer includes race. Creatinine is part of a basic or comprehensive metabolic panel, so eGFR appears on most routine blood work without any extra test.

Kidney disease usually causes no symptoms in its early stages. More than 1 in 7 adults in the United States, about 35 million people, have chronic kidney disease, and about 9 in 10 of them do not know it. A regular eGFR check is the simplest way to catch kidney problems early, when treatment can slow damage the most.

Normal eGFR by Age

Kidney function slowly declines with age, even in healthy people. After about age 40, eGFR drops by roughly 1 point each year. The sections below explain what a normal eGFR looks like for young adults, middle aged adults, older adults, and children.

1. Normal eGFR for Adults Ages 20 to 39

Young adults have the highest kidney function of any age group. The average eGFR is about 116 for adults in their 20s and about 107 for adults in their 30s. A normal result in this age group is 90 or higher. An eGFR below 90 at a young age is less common and is worth a closer look, especially with high blood pressure or diabetes.

People with a lot of muscle, such as athletes and bodybuilders, can have a higher creatinine and a slightly lower eGFR without any kidney problem. Creatine supplements and a large meat meal before the test can also lower eGFR for a short time. If your result looks low for your age, your doctor will often repeat the test or order a cystatin C test.

2. Normal eGFR for Adults Ages 40 to 59

The average eGFR is about 99 for adults in their 40s and about 93 for adults in their 50s. Kidney function starts its slow, natural decline in this age group. Type 2 diabetes and high blood pressure, the two most common causes of kidney disease, also become more common during these years and can speed up the drop in eGFR.

Diabetes causes about 1 in 3 cases of kidney failure in the United States. Our guide on Normal A1C Level by Age explains how to read the blood sugar test that protects your kidneys over time. High blood pressure causes about 1 in 4 cases, so both numbers matter for long term kidney health.

3. Normal eGFR for Adults 60 and Older

The average eGFR is about 85 for adults in their 60s and about 75 for adults 70 and older. An eGFR between 60 and 89 is common at this age and is often normal when there is no protein in the urine and no other sign of kidney damage. Doctors do not diagnose kidney disease from age related decline alone.

An eGFR below 60 is not considered normal at any age, even though it becomes more common after 70. Older adults also take more medicines that can affect the kidneys, such as ibuprofen, naproxen, and some blood pressure drugs. Your provider checks your eGFR before starting or changing many medicines and adjusts doses to keep your kidneys safe.

4. Normal eGFR for Children and Teens

Babies are born with low kidney function that rises quickly in the first months of life. A newborn’s eGFR is often 20 to 50, and it reaches adult levels of about 90 to 120 by age 2. Children and teens then keep a normal eGFR of 90 or higher. Doctors use a special formula for children called the bedside Schwartz equation.

Kidney disease in children is rare, but it can be linked to birth defects of the kidneys or bladder, frequent urinary tract infections, or inherited conditions. A child with swelling, foamy urine, or high blood pressure should be checked. Our pediatric care in Cypress includes blood pressure checks and lab tests when a child shows signs of kidney problems.

Average eGFR by Age Chart

This chart shows the average eGFR for each adult age group, based on National Kidney Foundation data, along with what is considered normal. All numbers are in mL/min/1.73m².

eGFR Stages of Chronic Kidney Disease

Doctors use eGFR to sort chronic kidney disease into stages. Stage 1 is an eGFR of 90 or higher with signs of kidney damage, such as protein in the urine. Stage 2 is 60 to 89 with kidney damage. Stage 3a is 45 to 59, and stage 3b is 30 to 44. Stage 4 is 15 to 29, and stage 5, also called kidney failure, is below 15.

A diagnosis of chronic kidney disease requires an eGFR below 60 for at least three months, or signs of kidney damage such as albumin in the urine. A urine albumin to creatinine ratio, or uACR, below 30 mg/g is normal. A uACR of 30 mg/g or higher on two of three tests shows kidney damage, even when your eGFR is normal.

Most people feel fine until stage 4 or 5. Later symptoms include swelling in the legs, ankles, or face, tiredness, foamy urine, itchy skin, poor appetite, nausea, and changes in how often you urinate. Many people with stage 3 kidney disease never progress to kidney failure, especially with good blood pressure and blood sugar control. Early care makes the biggest difference.

What Can Affect Your eGFR Results?

eGFR is an estimate, so several everyday factors can change your result. Dehydration from illness, heat, or low fluid intake can lower eGFR for a short time. A large meal of cooked meat within 12 hours of the test, intense exercise, and creatine supplements can raise creatinine and make eGFR look lower than it really is for a day or two.

Body size and muscle mass also matter. People with a lot of muscle can have a lower eGFR than their true kidney function, while people with very little muscle, including frail older adults and people after an amputation, can have a falsely high eGFR. A cystatin C blood test, which is not affected by muscle mass, gives a more accurate result in these cases.

Some medicines raise creatinine without harming the kidneys, such as trimethoprim and cimetidine. Others, such as ibuprofen, naproxen, and some contrast dyes used in imaging, can lower kidney function. Pregnancy raises eGFR by up to 50 percent. One low result is not a diagnosis, so doctors usually repeat the test within a few weeks to three months to confirm it.

When to Get Your Kidney Function Checked?

Every adult should have eGFR checked as part of routine blood work. A test at least once a year is advised if you have diabetes, high blood pressure, heart disease, obesity, a family history of kidney disease, or are over 60. The American Diabetes Association recommends a yearly eGFR and urine albumin test for everyone with diabetes, starting at diagnosis for type 2 diabetes.

See a provider sooner if you notice swelling, foamy or bloody urine, a big change in how much you urinate, or new high blood pressure. Doctors usually refer patients to a kidney specialist, called a nephrologist, when eGFR falls below 30, drops quickly over a year, or when uACR rises above 300 mg/g. Our guide on Chronic Disease Management explains how ongoing care works.

At Prime Healthcare of Cypress, we check your eGFR, review your urine results, and explain what your kidney numbers mean in plain language. Kidney function tests are part of annual physical exams in Cypress. Our chronic disease management in Cypress covers diabetes and high blood pressure care, and telemedicine in Cypress makes it easy to review your lab results from home.

How to Protect Your Kidney Function?

Most kidney damage comes from conditions you can control. The sections below explain how blood pressure and blood sugar control, along with healthy daily habits, help protect your eGFR as you age.

1. Control Your Blood Pressure and Blood Sugar

High blood pressure damages the tiny blood vessels inside your kidneys. Most adults with kidney disease aim for a blood pressure below 130/80. Our guide on Normal Blood Pressure by Age explains each blood pressure category. ACE inhibitors such as lisinopril and ARBs such as losartan lower blood pressure and also help protect the kidneys from further damage.

High blood sugar slowly scars the kidney filters. Most adults with diabetes aim for an A1C below 7 percent. Our post on Normal Blood Sugar Levels by Age explains daily blood sugar targets. Newer medicines called SGLT2 inhibitors, such as empagliflozin and dapagliflozin, can slow the decline in eGFR in people with diabetes or chronic kidney disease.

2. Daily Habits for Healthy Kidneys

Limit sodium to less than 2,300 milligrams a day, since extra salt raises blood pressure and strains the kidneys. Drink enough water to stay hydrated, unless your provider tells you to limit fluids. Avoid regular use of ibuprofen and naproxen, and ask your provider before taking any new supplement. Quit smoking, since smoking narrows blood vessels and lowers kidney blood flow.

Extra weight raises the risk of diabetes, high blood pressure, and kidney disease. A weight loss of just 5 to 10 percent can lower blood pressure and improve blood sugar control. If you need support, weight loss management in Cypress offers medically supervised plans. Regular exercise, good sleep, and a diet rich in vegetables, fruits, and whole grains also support healthy kidneys.

Frequently Asked Questions