Author
Celtic Self Storage
The most common question we hear from first-time customers is: "What size unit do I need?" That is perfectly understandable — it is hard to picture how much space your belongings will take up inside a closed room. A unit that is too small means frustration; one that is too large means unnecessary expense. This guide will help you find the sweet spot.
Rule number one: think in three dimensions
A storage unit is not just a floor area — it is a three-dimensional space. A 4 m² unit with a ceiling height of 2.5 m gives you 10 cubic metres of usable volume. The key is to use the full height, not just the floor.
Practical tip: If you stack furniture and boxes from floor to ceiling (leaving a walkway), you can fit as much into a 4 m² unit as you would into an 8 m² room with everything sitting flat on the ground.
Size guide — what fits where?
1–2 m² (wardrobe or closet)
Ideal for: documents, seasonal clothes, small sports gear
What fits:
- 10–20 moving boxes
- Suitcases and travel bags
- Sports equipment (skis, snowboards)
- 2–4 sets of car tires
- Seasonal clothing (5–10 vacuum bags)
- Small electronics
Who chooses this size: Students, anyone storing seasonal items, singles with a modest overflow of belongings.
Cost at Celtic: From 169–170 PLN/month
3–4 m² (small room)
Ideal for: contents of a studio flat, a minor renovation
What fits:
- Everything from a 1–2 m² unit, plus:
- A single bed (disassembled)
- A small sofa or armchair
- A desk and office chair
- A washing machine or dishwasher
- 20–30 boxes
- A bicycle
Who chooses this size: People moving out of a studio, students storing a dorm room's worth of items, small businesses with document archives.
5–7 m² (large room)
Ideal for: contents of a two-room flat, renovating one room
What fits:
- A full bedroom set (bed, wardrobe, chest of drawers)
- A three-seater sofa
- A dining table with four chairs
- Large appliances (fridge, washing machine)
- 30–50 boxes
- Garden equipment
Who chooses this size: Families mid-renovation, people between flats, businesses with larger stock.
8–10 m² (garage-sized)
Ideal for: contents of a three- or four-room flat, a business with a sizable inventory
What fits:
- Full furnishings from a large apartment
- An entire kitchen (cabinets, appliances)
- 2–3 beds
- A large wardrobe or walk-in closet's contents
- 50–80 boxes
- The whole family's sports gear
Who chooses this size: Families renovating a large flat or moving from a house, e-commerce businesses.
12–20+ m² (large garage or warehouse)
Ideal for: contents of a house, large business
What fits:
- Complete furnishings of a detached house
- Garden furniture, tools, barbecue
- A motorcycle or quad bike
- Full e-commerce stock
- Years' worth of company archives
Who chooses this size: Homeowners undergoing a major renovation, businesses with significant storage needs.
Quick-reference sizing table
| Situation | Recommended size | Approx. cost |
|---|---|---|
| Seasonal clothes + skis | 1–2 m² | From 169 PLN/month |
| Moving out of a studio | 3–4 m² | From ~250 PLN/month |
| Renovating one room | 4–5 m² | From ~300 PLN/month |
| Moving out of a 2-bed flat | 5–7 m² | From ~350 PLN/month |
| Full apartment renovation | 8–10 m² | From ~450 PLN/month |
| Moving out of a house | 12–15 m² | From ~600 PLN/month |
| Business / e-commerce | 10–20+ m² | Custom quote |
The most common sizing mistakes
Mistake 1: Choosing a unit that is exactly the right size
If the tool says 5 m², go for 6 m². Why? Because in practice:
- Boxes never stack as neatly as Tetris blocks
- You need a walkway to reach the back wall
- You may add more items during the rental period
Rule of thumb: Add 10–20 percent to your calculated requirement.
Mistake 2: Forgetting about a walkway
If you plan to visit your unit regularly (for example, to retrieve seasonal clothing), leave a corridor down the middle. A unit stuffed to the brim saves money on size but costs you an hour of rearranging every time you visit.
Mistake 3: Not disassembling furniture
An assembled wardrobe takes up two to three times more space than a disassembled one. A desk with its legs on is a logistical nightmare; without legs it is a flat board. Spend an hour on disassembly and you could save 2–3 m² of floor space.
Mistake 4: Storing things you do not need
Before you start packing, do a ruthless sort. That old TV, the broken chair, the boxes of things that "might come in handy one day" — they all take up space and cost you money every month.
Use the unit finder
Prefer not to do the maths yourself? Try our unit finder. Simply select the items you plan to store and the tool recommends the optimal unit size.
The tool accounts for:
- Type and quantity of furniture
- Number of boxes
- Household appliances
- Additional items (bicycles, tires, sports equipment)
How to fit more into a smaller unit
A few tricks from our team:
- Disassemble furniture — unscrew table legs, take apart bed frames, dismantle bookcases
- Use internal space — fill dresser drawers, the drum of a washing machine, and the inside of wardrobes
- Boxes on top — heavy and large items on the bottom, lightweight boxes stacked to the ceiling
- Stretch wrap on sofas — protects upholstery and compresses the profile
- Vacuum bags — reduce the volume of clothes and bedding by up to 70 percent
- Stand items upright — mattresses, boards, and tabletops stored on their edge save floor space
- Plan the layout — heavy or rarely needed items at the back, light or frequently needed items near the door
Changing size during your rental
At Celtic Self Storage, you can switch to a different unit size at any time during your rental. If after a month you realise your unit is too big (or too small), simply move to another one. Flexibility is at the core of how we work.
Summary
Choosing the right unit size comes down to accurately estimating the volume of your belongings and packing smartly. Remember:
- Think in 3D — use the full height of the unit
- Add a margin — 10–20 percent more than your calculation
- Disassemble furniture — you could save up to half the space
- Use the calculator — quick and precise
Need advice? Our team is happy to help you choose the right size. Renting a storage unit is straightforward — check out the range at Celtic Self Storage.
- Lomianki: 668 116 622
- Piaseczno: 606 914 856
Have questions? Check our FAQ or get in touch.
