Hamster: lifespan, size, diet and care
It sleeps during the day: it’s awake in the evening and at night. Syrian hamsters live alone; two will fight.
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How big it is
An adult is up to 18 cm (7 in) long, head and body.
Zoomed ×8: here you see the man up to 23.8 cm (9 in) off the ground
Before it arrives
- A cage with at least 100 × 50 cm (39 × 20 in) of floor, ideally on one level: bigger is better
- At least 25 cm (10 in) of bedding to dig burrows
- A wheel at least 30 cm (12 in) wide with a solid running surface, no bars
- Hidden nest boxes to sleep in during the day
- Hamster pellets, timothy hay and wood to chew
- A water bottle with a sipper tip and sturdy bowls
- A quiet spot at 18–26 °C (64–79 °F), away from TVs, computers and running water (they make ultrasound)
- Just one hamster: Syrians live alone and two will fight
Its home: temperature and light
- The room
- 18–26 °C (64–79 °F)
What it eats and how often
hamster mix and a few vegetables
- Adults: every day
Hamster pellets as the base (better than mixes, where it picks only the sweet bits), plus a teaspoon or two of vegetables, fruit and herbs a day, and timothy hay. Not much fruit: sugar makes it fat. Remove leftover food every day.
Vaccines and checkups
None: no vaccines are required or recommended for hamsters.
No vet source gives a fixed checkup schedule: ask a vet who knows its species how often a checkup is needed.
The care calendar
What to do, from the most frequent to the least.
- every dayFresh food and waterAdd a little hay, remove leftover food and clean the bottle.
- every 3 daysEvening checkFront teeth, nails and tail area; in the evening, when it's awake.
- every weekDeep clean the enclosureEvery day, remove wet bedding and leftover food. A full clean once a week if the cage is small; big setups only need it every few weeks. Put back a little of the old, clean bedding so it still smells like home.
Call the vet right away if…
If you see one of these signs, call your vet now: don’t wait for it to pass.
- Wet, dirty fur around the tail, with diarrhea
- Drools, eats less, or its front teeth look too long
- Breathes with difficulty, or has a runny nose or eyes
- A hot, red, painful swelling or a new lump
- Sits quietly in a corner, or loses weight or patches of fur
Frequently asked questions
How long does a hamster live?
Usually 2–3 years.
How big is a hamster?
An adult is up to 18 cm (7 in) long, head and body.
How much does a hamster weigh?
An adult usually weighs 110 g (3.9 oz) to 140 g (4.9 oz).
What does a hamster eat, and how often?
Hamster mix and a few vegetables. Hamster pellets as the base (better than mixes, where it picks only the sweet bits), plus a teaspoon or two of vegetables, fruit and herbs a day, and timothy hay. Not much fruit: sugar makes it fat. Remove leftover food every day. Adults: every day.
Does a hamster need vaccines?
None: no vaccines are required or recommended for hamsters.
When should a hamster see a vet right away?
Right away if you see one of these signs: wet, dirty fur around the tail, with diarrhea; drools, eats less, or its front teeth look too long; breathes with difficulty, or has a runny nose or eyes. The others are above, in “Call the vet right away if…”.
How old is a hamster in human years?
There’s no serious human-years chart for a hamster: the ones online don’t cite sources. What counts is where it is in its life: its senior years start at about 1.5 to 2.3 years old.
Tools for your hamster
Always ask your vet: this site helps you understand, it doesn’t replace a checkup.
Sources
- RSPCA, Hamster environment (checked on September 30, 2026)
- PDSA, Hamsters as pets (checked on September 30, 2026)
- Merck Veterinary Manual, Description and Physical Characteristics of Hamsters (checked on September 30, 2026)
- RSPCA, Hamster diet (checked on October 13, 2026)
- Merck Veterinary Manual, Routine Health Care of Hamsters (checked on October 13, 2026)
- PDSA, Giving your pet a health check at home (checked on October 13, 2026)
- Merck Veterinary Manual, Providing a Home for a Hamster (checked on October 13, 2026)
- Animal Diversity Web, Mesocricetus auratus (checked on October 13, 2026)
- Merck Veterinary Manual, Hamsters (checked on October 13, 2026)