How big does a Mastiff get? Adult weight is 120-230 lbs, and growing usually finishes around 24 months. The curve shows the weight to expect along the way.

Age	Expected weight
2 months	18-34.5 lbs
3 months	33.9-65 lbs
4 months	49.1-94.1 lbs
5 months	60.6-116.1 lbs
6 months	72-138 lbs
8 months	86.4-165.6 lbs
10 months	97.6-187.1 lbs
12 months	105.6-202.4 lbs
15 months	111-212.8 lbs
18 months	116.4-223.1 lbs
24 months	120-230 lbs

Typical range for a healthy puppy. Individual dogs can sit above or below it.

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Mastiff - Frequently Asked Questions

How big is a Mastiff? +

The Mastiff is a large breed, standing 27-30 in tall and weighing 120-230 lbs.

How much does a Mastiff weigh at 6 months? +

A Mastiff usually weighs 72-138 lbs at 6 months and reaches 120-230 lbs once fully grown, at around 24 months.

How long do Mastiffs live? +

The average lifespan of a Mastiff is 6-10 yrs.

How much does a Mastiff cost? +

Expect to pay $1,500-$3,500 for a Mastiff puppy, plus around $2,000-$3,500 per year for food, vet care, grooming, and supplies.

Is a Mastiff hypoallergenic? +

No, the Mastiff is not considered hypoallergenic and may trigger symptoms in people with dog allergies.

Is a Mastiff good with kids? +

Yes - Mastiffs are known for being gentle and patient with children, making them a solid family choice.

Is a Mastiff good for apartments? +

No - the Mastiff needs space and exercise that apartments rarely provide. A house with a yard is strongly recommended.

Is a Mastiff easy to train? +

The Mastiff is moderately trainable. Consistent, patient training from an early age works best.

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