Professional dog breeders created a standardized measurement system, which defines a large dog breed as weighing at least 50 pounds (22.6 kilograms) and having a minimum height of around 24 inches (61 centimeters).

Giant breeds are a minimum of 100 pounds (45.3 kilograms), and as you can imagine, their proportions are even greater. Many giant breeds are working dogs, which means they exist for a specific purpose such as herding, hunting or protection. While some of them can be a lot to handle, many like the Great Pyrenees are gentle giants.

So, dog lovers, let’s take a look at some of the world’s biggest dog breeds according to the American Kennel Club (AKC). Twelve are listed here by weight, plus a couple of Guinness World Record holders for good measure.

The Saint Bernard breed originated in the Swiss Alps, often portrayed with a small wooden barrel around its neck. Despite being one of the world’s largest dog breeds — it can weigh as much as 180 pounds (81.6 kilograms) — it’s agile and adept at search and rescue for people lost in the snow or buried by avalanches.

This big dog breed can weigh as much as 175 pounds (79.4 kilograms). This working breed is elegant, spirited and friendly.

Guinness World Record Holders

When it comes to Guinness World Record holders for the tallest dogs, the Great Danes take the cake — in fact, two named Zeus. The current record-holder is a 2-year-old Great Dane named Zeus who lives in Bedford, Texas. Zeus became the record holder for tallest living dog at 3 feet, 5.18 inches (1.046 meters) in March 2022.

But don’t confuse him with the tallest dog ever, who also was a Great Dane called Zeus. This Zeus was from Otsego, Michigan, and stood a bit taller at 3 feet 6.7 inches (1.12 meters). He died in September 2014.

Also adept at drafting, the Leonberger has a small, lion-like mane, hence the French name Leon. However, it originates from Leonberg, Germany, where Heinrich Essig tried to create a breed that looked like a lion, which was part of the crest of the town.

Although it later became a working dog, it first served as a companion dog for European royalty.

This smart and loyal working dog with an average weight of 150 pounds (68 kilograms) offers protection to livestock. Although their appearance can be intimidating, they are anything but.

These reserved dogs prefer to be a threatening presence rather than attack predators. Anatolian shepherds are still popular as guard dogs on ranches today.

If you’re a water person looking for a large dog, the Newfoundland is an excellent option. This powerful working dog, which can weigh up to 150 pounds (68 kilograms), has webbed feet and a water-repellent outer coat.

The breed first worked with Canadian fishermen pulling fishing nets out of icy water and for water rescue. In addition to its massive size, the Newfoundland is a trainable gentle giant.

Several mastiffs fit into the giant category. Representing the group here is the Bullmastiff, which can weigh up to 130 pounds (58.97 kilograms). Originally bred in the 19th century to guard private English game preserves and country estates, they respond well to training but can be stubborn, so early socialization and training are a must.

Other mastiffs include:

At about 130 pounds (58.97 kilograms), this giant terrier is imposing and intelligent. The Soviet government bred the Black Russian Terrier, aka Stalin’s dog, in the 1930s as a powerful guard and police dog. To this day, they retain those protective qualities and are very loyal to their families.

The Irish Wolfhound can weigh about 120 pounds (54.4 kilograms). While not the biggest, it is the tallest dog breed, according to the AKC, and originally served as a big-game hunter.

While their ancestors date back to ancient times, this giant breed first gained popularity by helping control the wolf population in Ireland. In the 1700s, Ireland’s wolves almost faced extinction, which in turn endangered the big dogs. They eventually rebounded and today are loving, family-friendly companions.

This giant with a gentle nature can weigh up to 115 pounds (52.2 kilograms) and is one of the well-loved giant breeds. Bred in Switzerland as a working dog, Bernese Mountain Dogs thrive in cold weather.

They worked on farms for carting or drafting — basically pulling a cart or wagon. Because of their good-natured personalities, they make excellent family dogs and companions.

This big dog weighs in at 110 pounds (49.9 kilograms). Similar in appearance to the Irish Wolfhound, the Scottish Deerhound is the royal dog of Scotland and is one of the tallest dog breeds in the world, standing at 30 to 32 inches (76 to 81 centimeters) tall.

This deer hunter runs deftly. Sensitive and deeply connected to family, it could suffer from separation anxiety, so this giant dog breed might be best for homebodies.

Cane corsos can weigh more than 100 pounds (45.4 kilograms). According to the American Kennel Club, they are “muscular and athletic [animals that move] with considerable ease and elegance. It has always been a property watchdog and hunter of difficult game such as the wild boar.”

Originally from Sicily in southern Italy, this Italian Mastiff became wildly popular in ancient Rome. Then, it nearly disappeared sometime during World War II.

After being rediscovered in a remote Italian village in the 1970s, a concerted effort by lovers of the breed saw them rebound and reintroduced to America in the 1980s. They tend to be wary of strangers but protective of their own people.

Second only maybe to a polar bear, the Great Pyrenees is readily recognizable by its puffy white coat. Despite appearances, its thick double coat is easy to maintain as it’s dirt- and tangle-resistant.

This majestic breed is impressive in size — it can weigh more than 100 pounds (45.4 kilograms) — and originally worked alongside shepherds to protect livestock. Pyrenees are patient and independent but also will fearlessly fight off predators.