The liver is the body’s largest and heaviest internal organ. It serves many important purposes, including regulating levels of chemicals in the blood, making bile to digest fats, and making cholesterol, blood plasma proteins, and immune factors. In adults, the liver weighs a little more than 3 pounds.

The liver varies in size as you age and certain health conditions can enlarge it.

Men tend to have a larger liver size than women. This is usually because men’s bodies tend to be larger. While liver sizes can vary slightly, there are some studies about the average liver size by age.

One such study was published in the journal Indian Pediatrics. The researchers performed ultrasound evaluation of 597 healthy children between the ages of 1 and 12 years.

The following are the results of the study measuring the average liver length for boys:

AgeLiver length (Boys)
1 to 3 months2.6 in. (6.5 cm)
3 to 6 months2.8 in. (7.1 cm)
6 to 12 months2.6 in. (6.5 cm)
1 to 2 years3.4 in. (8.6 cm)
2 to 4 years3.5 in. (9.0 cm)
4 to 6 years4.1 in. (10.3 cm)
6 to 8 years4.3 in. (10.8 cm)
8 to 10 years4.7 in. (11.9 cm)
10 to 12 years5.7 in. (12.6 cm)

The following are the results for liver length in girls:

AgeLiver length (Girls)
1 to 3 months2.4 in. (6.2 cm)
3 to 6 months2.8 in. (7.2 cm)
6 to 12 months3.1 in. (7.9 cm)
1 to 2 years3.3 in. (8.5 cm)
2 to 4 years3.5 in. (8.9 cm)
4 to 6 years3.9 in. (9.8 cm)
6 to 8 years4.3 in. (10.9 cm)
8 to 10 years4.6 in. (11.7 cm)
10 to 12 years4.8 in. (12.3 cm)

Liver size can vary by sex, body mass index, height, amount of alcohol consumed, and many other factors.

An older study published in the Journal of Ultrasound in Medicine measured the average liver diameter of more than 2,080 male and female participants between 18 to 88 years old at the midclavicular line, which is an imaginary line moving down your body starting from the middle of your collarbone. The study’s results found the following:

AgeAverage liver diameter
18 to 25 years5.4 in. (13.6 cm)
26 to 35 years5.4 in. (13.7 cm)
36 to 45 years5.5 in. (14.0 cm)
46 to 55 years5.6 in. (14.2 cm)
56 to 65 years5.7 in. (14.4 cm)
Greater than 66 years5.5 in. (14.0 cm)

The study represents one of the largest populations studied regarding average liver length, and concluded that the average liver size in adults was 14 cm.

Doctors use imaging studies to estimate liver size. Sometimes, when the liver is extremely enlarged, a doctor can identify the enlargement on an X-ray. When they want greater accuracy, they’ll usually use ultrasound.

Ultrasound is a painless imaging technique that uses sound waves to compare solid organs with other surroundings, such as blood. Because ultrasound uses sound waves, it doesn’t expose a person to radiation like many imaging techniques do.

Typically, a person who specializes in ultrasound known as an ultrasonographer or a liver doctor will perform the ultrasound. You’ll lie down and they’ll use a special wand device to transmit images of the liver to an ultrasound screen. The size of the liver is measured on the screen.

The liver isn’t a proportional organ. Its lobes are different sizes and can be larger and smaller in areas depending on where the ultrasound professional is taking measurements. These differences can cause some variance accuracy. A doctor will also usually compare these results with other imaging studies. These may include a CT scan.

The condition of having an enlarged liver is called hepatomegaly. When the liver gets larger, it doesn’t always cause symptoms. Some people may report a feeling of abdominal fullness or pressure.

A variety of medical conditions can cause an enlarged liver.

Acute hepatitis

An inflammation of the liver caused by one of the five hepatitis viruses. The body may clear the virus, or a person can develop chronic hepatitis, such as hepatitis B or hepatitis C.

Biliary atresia

Biliary atresia is a rare condition that affects the size or presence of the bile ducts. It often requires surgery to treat.

Cirrhosis

Cirrhosis can be the result of chronic alcohol consumption, hepatitis, or other liver-related conditions. The main treatments are to slow the progression of further scarring.

Fatty liver

A fatty liver is a condition that can occur due to excess weight or chronic alcohol consumption. Only a liver transplant can treat fatty liver.

Infectious mononucleosis

Infectious mononucleosis is a viral disease caused by the Epstein-Barr virus. Most people will feel better in two weeks to several months.

Liver cancer

Various cancers can affect the liver. Treatments depend upon the cancer type but may include surgery and radiation.

Right heart failure

Right heart failure can cause excess fluid to build up in the liver’s blood vessels. Treatments usually aim to reduce fluid buildup and improve heart function in this serious heart failure side effect.

Additionally, rare diseases like Gaucher’s disease, Wilson’s disease, or Niemann-Pick disease can cause liver enlargement. Treatments for these diseases depend upon the particular condition.

If you have an enlarged liver, your doctor will likely consider your overall symptoms, medical history, and imaging and blood studies before making a diagnosis.

Because your liver is so vital to your health, you should keep it healthy:

  • Maintain a healthy weight. Excess weight can lead to a condition called non-alcoholic fatty liver disease.
  • Exercise at least 30 minutes a day. Exercise helps to burn excess fat for energy. This also reduces the likelihood you’ll have fatty liver disease. Even if you feel like you don’t have 30 minutes to spare, try breaking up exercise into two 15-minute sessions or three 10-minute sessions.
  • Don’t smoke. Smoking contains toxins that can injury your liver cells and most other cells in your body. Quitting can be very difficult, but a doctor can help you create a plan that’s right for you.
  • Limit alcohol consumption. If you do drink, one drink a day for women and no more than two drinks a day for men is a moderate, liver-friendly amount. If you already have a condition that affects your liver function, a doctor may suggest you not drink at all.
  • Avoid toxins. Chemicals like cleaning products, aerosols, insecticides, and additives all contain toxins that can damage your liver. Take proper safety precautions, such as wearing a mask and gloves, and use them in a ventilated area.
  • Protect against hepatitis. Hepatitis B and C are two forms of liver disease that can cause chronic damage. They’re usually transmitted sexually or from sharing needles with an infected person.
  • Don’t mix drugs and alcohol. The liver filters many medications as well as alcohol. Combining the two can place too much demand on your liver and lead to damage. If you take a lot of medicines, including supplements, it’s a good idea to review the list with a doctor to ensure you aren’t overdoing it.
  • Get vaccinated. Vaccines exist for hepatitis A and hepatitis B. Getting these vaccines can protect you against these diseases to protect your liver.

If you have more questions about how to keep your liver healthy, talk to a doctor.

The liver is an important organ that grows as you age. If the liver is enlarged, a doctor may perform various imaging studies and other tests to determine an underlying cause. If you’re concerned your symptoms could be the result of liver enlargement, talk to a doctor.