A Smart Way to Fit a 100 cm Gerbil Tank Into a Small Space
Small-space gerbil tank planning starts with one number: about 775 square inches of floor for a pair. Here’s how to find room for it at home.
Table of Contents
A 100 cm gerbil tank in a small home: what fits
For a pair of Mongolian gerbils, Woodgreen Pets Charity sets the minimum tank at 100 × 50 × 50 cm. That floor is the number to plan your room around.
📊 Tested / Spec: A 100 × 50 cm floor is 5,000 cm² — about 39.4 × 19.7 inches, 775 square inches or 5.4 square feet. (Our arithmetic.)
If you’re still deciding
Measure your spot first (Section 3), then check it’s safe (Section 4). For everything else that goes in the tank, see our full gerbil tank setup guide.
If your gerbils already live in a smaller tank
That’s fixable — Section 7 covers the upgrade.
If you live in California
California bans gerbils as pets and issues no pet permits. Check California’s restricted species rules before you buy.
🩺 Health Note: This is general information, not a substitute for an exam by a vet experienced with gerbils. If a gerbil seems unwell in the heat, move the tank somewhere cooler and call that vet.
Why the floor is the part you can’t shrink
Woodgreen’s reasoning is simple: Mongolian gerbils are built to dig, so floor space matters more than height or shelves.
What the standards say for a pair
| Source | Figure for two gerbils | Key Detail |
|---|---|---|
| Merck Veterinary Manual | About 5 gallons per gerbil (a 10-gallon tank for two) | A rule of thumb |
| RSPCA | No floor figure | Gerbilarium ideally about 50 cm high, with 20–30 cm of bedding |
| Woodgreen Pets Charity | 100 × 50 × 50 cm (three gerbils: 120 × 50 × 50 cm) | Current rescue guidance |
Figures from each organization’s gerbil care page, checked October 2026.
For the full comparison, see how each source sizes a tank for a pair.
🔄 Outdated Advice: Merck’s 5-gallon rule of thumb sits far below current UK rescue guidance.
Why height can’t stand in for floor
🔍 Why It Works: Wild gerbils dig large, deep burrows (RSPCA). Height adds bedding depth, not the floor area Woodgreen says matters most.
Measure your spot before you buy the tank
Before you buy a 100 cm tank for your gerbils, measure four things: surface, height, weight and reach.
The four measurements
- Surface. Check the listed outside size, not the inside 100 × 50 cm.
- Height. About 50 cm (RSPCA), plus the lid and room to lift it.
- Weight. Check the furniture maker’s stated load limit rather than guessing.
- Reach and cleaning room. The RSPCA advises a deep clean every two to three weeks. Leave space nearby for a carrier and bedding bags.
How much bedding 100 cm really takes
📊 Tested / Spec: At the RSPCA’s 20–30 cm depth, a 100 × 50 cm floor holds about 100–150 litres of bedding by volume. At Woodgreen’s 20–25 cm, it’s about 100–125 litres. Both are our arithmetic.
Here’s how much bedding your tank can hold once it’s in place.
Where a gerbil tank can go in a small home
The safest spot for a gerbil tank is quiet, dry and draught-free, in a room around 20–24°C, the RSPCA’s range for gerbils.
Spots to rule out
- Beside a window or in direct sun. Woodgreen still wants natural daylight in the room.
- Next to a radiator or heater.
- Draughty hallways.
- Near a TV, computer screen or speakers. Gerbils communicate in ultrasound (RSPCA).
- Kitchen sinks and bathrooms — running water emits ultrasound.
- Within reach of cats or dogs, unless the room can be shut off (Woodgreen).
These verdicts apply the RSPCA’s gerbil housing guidance and Woodgreen’s advice to typical small-home rooms.
Is a bedroom OK?
Woodgreen advises against a bedroom someone sleeps in, because gerbils can be active overnight.
If the room runs hot
⚠️ Watch Out: The Royal Veterinary College’s exotics service warns that tanks in direct sunlight easily overheat. If a gerbil seems unwell in the heat, move the tank somewhere cooler and call a vet experienced with gerbils now.
No exotics vet yet? Use the AEMV directory to find a vet who sees gerbils before you need one.
Make 100 cm feel bigger without adding shelves
For gerbils, the extra space you’re looking for is downward, in the bedding — not upward on shelves.
Depth is your third dimension
The RSPCA’s 20–30 cm of bedding lets gerbils build their own burrows. Add a dark nest box with several entrances, plus one more hide than you have gerbils — three for a pair.
Why shelves and multi-level tanks backfire
⚠️ Watch Out: Woodgreen warns that mesh shelves can damage feet, and a weaker gerbil can get stuck under a solid shelf while digging up. The keeper site gerbilcare.co.uk advises no more than two levels, linking extra levels to fighting.
Fitting a wheel in a 50 cm tank
The RSPCA wants a large, solid, axle-free wheel, and Woodgreen lists a 12-inch upright one.
📊 Tested / Spec: A 12-inch wheel stands about 30.5 cm tall. A 50 cm tank with 20 cm of bedding leaves about 30 cm above it — our arithmetic, so check the fit or mount it in a topper.
For sizes, see choosing a solid gerbil wheel.
Ready-made 100 cm enclosure or a converted tank?
For a pair of gerbils, either route works if the inside floor reaches 100 × 50 cm.
Ready-made options at 100 × 50 cm
| Option | Listed size | Key Detail |
|---|---|---|
| Bucatstate enclosure 2.0 | 100 × 50 × 52.5 cm | On Woodgreen’s list for two |
| Bucatstate enclosure 3.0 | 100 × 50 × 52 cm or 120 × 60 × 62 cm | Larger size suits three |
| Diversa aquarium | 100 × 50 × 50 cm | Needs a DIY mesh lid |
| Skyline Nagarium Marrakech | 115 × 50 × 50 cm | 15 cm longer — measure first |
Sizes from Woodgreen’s recommended list; check the current listing in your country.
Converting a tank: the lid is the job
Woodgreen says a standard fish-tank lid isn’t suitable. Build a screwed wooden frame with 1 cm × 1 cm welded mesh, fixed on the inside to limit chewing.
What about the Ikea Detolf?
Woodgreen lists it at 163 × 43 cm, for three gerbils, secondhand only. At that length, it’s a poor pick when space is tight.
If a 100 cm tank truly won’t fit
If 100 cm won’t fit, the closest common option for two gerbils is a 40-gallon breeder tank.
The 40-gallon breeder, honestly
📊 Tested / Spec: A 40-gallon breeder’s nominal 36 × 18 inch floor is 648 square inches — about 84% of 100 × 50 cm. That’s our arithmetic.
Chewy calls 40 gallons often the minimum for two. It’s still below Woodgreen’s rescue figure.
What not to do
- Don’t keep one gerbil to save room. Merck says living alone may be stressful and recommends pairs — here’s why one gerbil isn’t the space-saving answer.
- Don’t stack shelves to make up the difference (Section 5).
Already have a smaller tank?
Plan the upgrade; meanwhile, the RSPCA suggests more enrichment and hiding places if gerbils dig repetitively in one corner.
Quick answers about gerbil tanks in small spaces
1. What size tank do two gerbils need?
Woodgreen sets a gerbil tank of 100 × 50 × 50 cm for two; Merck’s older rule of thumb is about 10 gallons.
2. How big is a 100 cm gerbil tank in inches?
A 100 × 50 cm gerbil tank floor is about 39.4 × 19.7 inches, or roughly 775 square inches.
3. Is a 40-gallon breeder big enough for two gerbils?
A 40-gallon breeder gives about 84% of a 100 × 50 cm floor — Chewy’s common minimum, below Woodgreen’s figure.
4. How much bedding does a 100 cm gerbil tank need?
At the RSPCA’s 20–30 cm depth, a 100 × 50 cm gerbil tank holds roughly 100–150 litres of bedding.
5. Does a 100 cm gerbil tank need a special lid?
Yes. Woodgreen says a standard fish-tank lid isn’t suitable; use a screwed wooden frame with 1 cm welded mesh.
6. Where should a gerbil tank go in a small flat?
Keep a gerbil tank away from windows, radiators, TVs and running water, in a dry room around 20–24°C.
7. Can a gerbil tank go in my bedroom?
Woodgreen advises against a gerbil tank in a bedroom someone sleeps in, because gerbils can be active overnight.
8. Can I add shelves to a small gerbil tank?
Woodgreen warns against mesh and solid shelves in a gerbil tank; deeper bedding adds usable space more safely.
9. Can one gerbil live in a smaller tank instead?
No. Merck says living alone may be stressful for gerbils and recommends pairs, so size the tank for two.
10. Are gerbils legal in California?
No. California’s Department of Fish and Wildlife lists gerbils among animals not allowed as pets and issues no pet permits.
Your next step: measure the spot tonight
Grab a tape measure and check the four things from Section 3: surface, height, weight and reach. If 100 × 50 cm fits, you’ve solved the hardest part of a good gerbil setup.
If it doesn’t, a smaller tank today can still be upgraded. Keep your pair together, give them deep bedding, and skip the stacked shelves.
