Great Dane Vs English Mastiff

If you are choosing between a Great Dane and an English Mastiff, the difference between them is bigger than the numbers suggest. One is a tall, graceful athlete who fills a doorway with height. The other is a deep, powerful giant who fills it with sheer breadth. This guide covers the size difference, the growth timelines, and the temperament that decides which giant fits your life.

What is the difference between a Great Dane and an English Mastiff?

The main difference between a Great Dane and an English Mastiff is build. A Great Dane is taller and leaner, standing 30 to 32 inches for males and 28 to 30 inches for females, with a typical adult weight of 140 to 175 pounds for males and 110 to 140 pounds for females. An English Mastiff is shorter through the leg but far heavier and broader, with males standing 30 inches and up at 160 to 230 pounds and females standing about 27 and a half inches and up at 120 to 170 pounds.

Temperament follows the frame. Danes tend to be playful and springy well into adolescence, while Mastiffs are famously steady, quiet and content to lie in one spot for hours. Both mature slowly, so the growth years matter enormously.

Great Dane and English Mastiff at a glance

Here is the side by side picture most Dog Parents want before committing.

Feature	Great Dane	English Mastiff
Male height	30 to 32 inches	30 inches and up
Female height	28 to 30 inches	27 and a half inches and up
Male weight	140 to 175 lb	160 to 230 lb
Female weight	110 to 140 lb	120 to 170 lb
Build	Tall, lean, athletic	Broad, deep, massive
Energy level	Moderate with playful bursts	Low and steady
Drool	Moderate	Generous
Full maturity	About 2 to 3 years	About 2 and a half to 3 years

What makes a Great Dane grow the way it does

The Great Dane grows upward first. Bred for real speed, the Dane carries height on comparatively fine legs, and that frame arrives fast. A Dane puppy can gain three to five pounds a week through the middle of the first year, one of the steepest growth curves in the dog world, which is why Dane parents hear so much about steady feeding. A young Dane often looks all legs and elbows at eight or nine months, with a narrow chest that has not caught up yet. That gangly stage is normal and resolves as the chest deepens through the second year.

What makes an English Mastiff grow the way it does

The English Mastiff grows outward as much as upward. This is a breed built for mass, with a broad skull, a deep chest and heavy bone throughout, so a Mastiff puppy piles on weight rather than height. It is not unusual for one to pass 100 pounds around six months while still behaving like a clumsy baby. Because so much weight arrives so soon, the Mastiff growth years ask more of developing joints than almost any other breed. Many also stay puppyish in the head past two years, inside an adult sized body.

Great Dane growth chart, month by month

Treat this as a guide, not a report card.

Age	Male weight	Female weight
2 months	25 to 35 lb	20 to 30 lb
3 months	40 to 50 lb	35 to 45 lb
4 months	55 to 70 lb	50 to 60 lb
6 months	85 to 105 lb	70 to 90 lb
9 months	105 to 130 lb	90 to 110 lb
12 months	120 to 145 lb	100 to 125 lb
18 months	135 to 165 lb	105 to 135 lb
2 years plus	140 to 175 lb	110 to 140 lb

English Mastiff growth chart, month by month

Mastiff numbers run heavier at every stage, with a wide spread between individuals.

Age	Male weight	Female weight
2 months	30 to 40 lb	25 to 35 lb
3 months	50 to 60 lb	40 to 50 lb
4 months	65 to 85 lb	55 to 70 lb
6 months	100 to 120 lb	80 to 100 lb
9 months	130 to 155 lb	100 to 125 lb
12 months	150 to 175 lb	110 to 140 lb
18 months	160 to 200 lb	120 to 155 lb
2 years plus	160 to 230 lb	120 to 170 lb

When do Great Danes and English Mastiffs stop growing?

A Great Dane reaches most of its adult height by around 18 to 24 months, then keeps adding chest depth and muscle until roughly two and a half to three years of age. An English Mastiff follows a similar height timeline but packs on substance for longer, often until three years. In both breeds height finishes well before the body looks finished, so a lanky twenty month old Dane and a rangy two year old Mastiff are both right where they should be.

Why the growth window matters more for giant breeds

Growth plates, the soft areas at the ends of the long bones, stay open through much of the first year and close later in giant breeds than in smaller dogs. While they are open, every extra pound and every hard landing asks more of a frame that is still forming. Dogs with an expected adult weight of 130 pounds and above keep developing for roughly 24 to 30 months, which is why lean feeding, sensible exercise and daily joint support carry so much weight for these two breeds.

How much should a Great Dane or English Mastiff eat while growing?

Giant breed puppies do best on steady, moderate growth. A few habits make a real difference for both breeds:

• Choose a complete food formulated for large or giant breed puppies, which balances calories, calcium and phosphorus for steadier growth.
• Split the daily amount into three meals while young, then two as an adult.
• Feed to a lean body condition. You should feel the ribs easily under a light layer.
• Resist feeding for size. A bigger puppy is not a healthier puppy, and adult size is written in the genes anyway.
• Ask your veterinarian to confirm the daily amount at each checkup.

How to check body condition in ten seconds

The scale tells you weight, but body condition tells you health, and on a giant breed it is the number that matters.

• Ribs. Run your hands along the sides. You should feel the ribs under a thin layer. If you have to press, ease back on food.
• Waist. From above, you want a clear waist that tucks in behind the ribs.
• Tuck. From the side, the belly should rise toward the back legs rather than hang level.

Growth safe exercise for a giant breed puppy

Both breeds need movement, but during the fast growth months the goal is regular, moderate activity rather than repeated hard impact. The Dane will ask for more of it. The Mastiff will happily ask for less.

• Favour free play, sniffing walks and gentle exploring on soft ground such as grass.
• Keep long runs, forced jogging and repeated jumping moderate while the growth plates are open.
• Lift or ramp your puppy in and out of the car rather than letting them leap down.
• Add early training and scent games, which satisfy a young giant without pounding on joints.
• Let your puppy rest fully between bursts. Growing bodies do their work while sleeping.

Protecting giant joints during the growth years

Both breeds carry more weight through their joints than nearly any other dog, and they carry it while the frame is still forming. Supporting healthy joint development through those years is one of the simplest habits you can build.

Alongside lean feeding and sensible exercise, many giant breed parents add a daily joint support chew made for large and giant breeds. MoveGuard Growth is built for exactly this stage. It combines nine actives, including New Zealand Green Lipped Mussel, glucosamine, chondroitin, MSM and hyaluronic acid, to support the developing joints of young large and giant breed dogs across the roughly 8 to 30 month growth window. You dose by expected adult weight, so both Danes and Mastiffs sit at three chews a day. It comes grain free, arrives as a 90 chew jar at about $39.99 on subscription, and is backed by a 60 day guarantee. Many parents then move across to MoveGuard Adult and keep the routine going.

Signs your giant breed puppy is growing on track

You do not need a weekly weigh in. Look for a bright, alert puppy with a waist you can see from above, ribs you can feel with light pressure, smooth even movement, and a healthy appetite. If you notice limping, stiffness after rest, splaying legs on smooth floors, or a sudden growth surge, a quick conversation with your veterinarian lets you adjust food or activity early.

A simple growth game plan, stage by stage

Raising a sound Dane or Mastiff takes the right emphasis at the right time, not a complicated program.

8 weeks to 4 months. Foundation stage. A complete large or giant breed puppy food, three calm meals a day, early socialisation, and short bursts of free play on soft ground. Put down rugs and runners now, before your puppy is heavy enough to hurt themselves slipping.

4 to 8 months. Growth is quickest here and your puppy may look leggy and comical. Keep feeding lean, keep exercise moderate, and build steady habits around stairs and car entry. This is the natural point to begin a daily joint support routine.

8 to 18 months. Height nears its peak while muscle starts to arrive. Match portions to a lean body condition, because a teenage appetite outpaces need. Danes want more outlet than Mastiffs here, so give it in short, playful bursts.

18 months to 3 years. The lanky adolescent becomes a genuine giant. Growth slows while chest and muscle continue to develop, especially in Mastiffs.

Common growth mistakes to avoid

Most growth troubles in giant breeds come from a few avoidable habits.

• Overfeeding for size. Extra weight loads developing joints at the wrong moment. Feed lean and let size arrive on its own schedule.
• Skipping large or giant breed puppy food. These formulas control calcium and calories for steady growth. Confirm the food with your veterinarian.
• Too much hard exercise, too young. Long runs and repeated jumping ask a great deal of open growth plates on a 120 pound puppy.
• Leaving floors bare. Rugs and mats around food bowls protect a heavy puppy from awkward splays and falls.
• Waiting for a problem before supporting joints. The growth window is the ideal time to support developing joints, not the months after.

Temperament, and which giant might suit your home

Both breeds are gentle and both are enormous. The real difference is the daily rhythm they bring into your house.

The Great Dane is playful, sociable and expressive. Danes lean on people, follow you room to room, and keep a goofy streak well into their third year. They want company, they get bored alone, and they will happily attempt your lap at 150 pounds. A daily walk, some free play and a warm household satisfies a Dane completely.

The English Mastiff is calm, watchful and profoundly steady. Mastiffs are quiet dogs who prefer to lie near the door and observe, naturally protective without much noise about it. They need less exercise and more space, and they drool with real commitment. Their slow mental maturity means training should be patient, consistent and started early, while your puppy grows into a body that will soon outweigh you.

Both breeds live shorter lives than most dogs, typically around seven to ten years, one more reason the growth years deserve real care.

Frequently asked questions

The bottom line

Choose the Great Dane if you want height, playfulness and a sociable shadow. Choose the English Mastiff if you want mass, quiet and a calm guardian content to lie at your feet. Both grow for two and a half to three years, both need lean feeding and gentle exercise through that window, and both reward the care you put into the early years with a comfortable, confident adulthood.

Want the simple roadmap in one place? Grab our free Big Dog Growth Guide for the growth window checklist, feeding framework and joint safe exercise limits, all written for large and giant breeds.

This article is for general educational purposes only and is not veterinary advice. It is not intended to diagnose, treat, cure or prevent any disease. Always consult your veterinarian about your dog’s individual health, nutrition and supplement needs. These statements have not been evaluated by the Food and Drug Administration.