How big does a Bullmastiff get?

A full-grown Bullmastiff typically stands 61–69 cm (24.0–27.2 inches) tall at the shoulder and weighs 41–59 kg (90.4–130.1 lbs). Bullmastiff is considered a giant breed and may take up to 18–24 months to reach full size.

What is the lifespan of a Bullmastiff?

The average lifespan of a Bullmastiff is 7–9 years. Giant breeds typically have shorter lifespans than smaller breeds. Maintaining a healthy weight is one of the most important factors in extending your dog's lifespan — overweight dogs can lose 1–2 years of life expectancy.

What are the personality traits of a Bullmastiff?

Bullmastiff are known for being loyal, courageous, calm, affectionate. They are generally good with children and make excellent family dogs. They are moderately trainable with consistent positive reinforcement. They need plenty of space and exercise, making them better suited for homes with yards.

Is a Bullmastiff a good choice for apartments and families?

A Bullmastiff is a giant breed that typically needs more space and exercise, so they may not be ideal for small apartments. They are generally good with kids and make great family companions. They are a low-shedding breed, which is great for keeping your home clean.

What are common health issues for giant breed dogs like the Bullmastiff?

Giant breeds like the Bullmastiff face increased risks of bloat (GDV), hip/elbow dysplasia, heart conditions, and bone cancer. Their large size puts extra stress on joints, making weight management critical. Keeping your dog at an ideal weight is the single most effective way to reduce the risk of many of these conditions. Use our BCS assessment tool above to check your dog's condition.

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Bullmastiff Weight & Calorie Guide

Q: How many calories does a Bullmastiff need per day?

A typical adult Bullmastiff weighing about 50 kg needs approximately 2106–2632 kcal per day, depending on activity level and neuter status. Puppies and very active dogs need more, while seniors and neutered dogs need less. Use our breed-specific calculator for an exact number.

Giant Breed

Quick Answer

A healthy adult Bullmastiff weighs 41–59 kg (90.4–130.1 lbs), according to the AKC breed standard. Puppies reach 50% of adult weight by 8–12 months and full weight by 18–24 months.

Source: AKC breed standard, WSAVA nutrition guidelines

Quick Facts

Ideal Weight

41–59 kg

(90.4–130.1 lbs)

Size Category

giant

Breed Type

Daily Calories

~2106–2632 kcal

Adult, neutered

Free Tools

BCS Assessment Calorie Calculator

Ideal Weight Range

41 kgto59 kg

90.4 lbsto130.1 lbs

UnderweightIdealOverweightObese

Data:AKC breed standard·WSAVA guidelines

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Puppy Weight Predictor

For puppies under 12 months. Enter your puppy's current weight and age to predict adult weight.

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How the puppy weight predictor works

This predictor uses growth milestone data from Salt et al. (2017), published in Veterinary Record, which tracked the weight development of dogs across five size categories from birth to adulthood. By comparing your puppy's current weight against the expected growth percentage for their age and size category, we estimate their adult weight range.

Factors that affect adult weight

Genetics play the largest role, but nutrition, neutering status, and overall health also influence growth rate. Puppies fed excessive calories during rapid growth phases may exceed their genetic weight potential, while underfed puppies may not reach it. Large and giant breeds grow more slowly than toy and small breeds, reaching full size at 18–24 months rather than 10–12 months.

Data source: Salt et al. (2017) "Growth patterns of commercial kennel dogs" Veterinary Record • AKC breed standards

Bullmastiff Health & Weight Management

Bullmastiff are powerful, muscular guardian dogs with a calm, dignified demeanor. They are among the most obesity-prone giant breeds — their stocky build and moderate energy level make weight gain easy and dangerous. Excess weight stresses joints (hip/elbow dysplasia is common), worsens breathing (brachycephalic tendencies), and increases cancer risk. Bloat (GDV) is also a serious concern in this deep-chested breed.

Exercise: 30–40 minutes of moderate daily walks. Bullmastiffs are not endurance athletes; short, gentle walks are ideal. Avoid exercising in hot weather and never force running. Swimming is good if your Bullmastiff tolerates water. Mental stimulation through training sessions is important.

Feeding tips: Bullmastiffs are professional beggars with a gentle but persistent approach. Measure every meal with a scale. Feed 2–3 smaller meals daily to reduce bloat risk. Use slow-feeder bowls. Choose a large/giant-breed formula with controlled fat content. Avoid table scraps entirely.

Keeping your Bullmastiff at a healthy 90–130 lbs (41–59 kg) is critical for joint, cardiac, and respiratory health. Use PawScale’s calorie calculator for Bullmastiffs to set exact daily limits, check body condition with our BCS assessment, and follow the crate size calculator.

Data source: AKC breed standard

Data source: AKC breed standard • Last updated: 2026-08-12

Is your Bullmastiff at a healthy weight?

59% of dogs are overweight — can you tell? Take our free 2-minute Body Condition Score assessment.

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Bullmastiff Calorie Calculator

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Frequently Asked Questions

How much should a Bullmastiff weigh?

The ideal weight for a Bullmastiff is 41–59 kg (90.4–130.1 lbs). Giant breeds have slower metabolisms, so weight management is especially important. Use our calorie calculator above to get personalized feeding recommendations.

How many calories does a Bullmastiff need per day?

A typical adult Bullmastiff weighing 50 kg needs approximately 2106–2632 kcal per day, depending on activity level and whether they are neutered. Use our breed-specific calculator above for an exact number based on your dog's details.

Is my Bullmastiff overweight?

59% of dogs are overweight, and most owners cannot tell just by looking. Check your Bullmastiff's Body Condition Score (BCS) — if you can't easily feel their ribs or they have no visible waist from above, they may be overweight. Take our free 2-minute BCS assessment above to find out.

When does a Bullmastiff reach full adult weight?

Bullmastiff puppies reach 50% of their adult weight by 8–12 months and typically reach full adult weight by 18–24 months, according to AKC growth guidelines. Small breeds mature faster than large breeds.

What size crate does a Bullmastiff need?

A Bullmastiff typically needs a 48-inch crate based on breed size. Use PawScale's free crate size calculator for a personalized recommendation.

References & data sources

1. AKC Official Breed Standard — Bullmastiff. akc.org

2. Salt C, et al. “Estimating the expected growth of dogs.” Vet Record, 2017;180(15):376.

3. National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, 2006.

4. Laflamme DP. “Development and validation of a body condition score system for dogs.” Canine Practice, 1997;22(4):10–15.

5. WSAVA Global Nutrition Guidelines; Association for Pet Obesity Prevention (APOP) 9-point BCS scale.

Last reviewed: September 2026

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