Rent a storage unit: The comprehensive guide to calculating the right size

When you are looking for a storage unit that fits your needs, choosing the right size is what makes the difference between space well used and money wasted. A reasonably accurate calculation makes sure everything you put into storage actually fits, while stopping you from paying for square metres you will never use.

Rule of thumb: you need roughly 10% – 15% of your living space

The average German home is around 90 m², so most full moves and clear-outs are covered by a unit of roughly 9 to 14 m². If you only want to free up space at home rather than empty it completely, 2 to 3 m² is usually plenty.

Find out how much space you need: just read it off the table

Storage units are usually between 2 and 3 metres high, and every household has a different volume. We have put together a table showing roughly how big a storage unit needs to be, depending on your living situation. One thing to know if you are new to Germany: apartments here are described by their total number of rooms, not bedrooms. A "3-room apartment" (3-Zimmer-Wohnung) means a living room plus two further rooms — what would be called a 2-bedroom flat in the UK or US. Kitchen and bathroom are never counted. The unit "wardrobes (60 x 85 x 200 cm)" is only partly helpful — almost nobody stores 35 wardrobes — but it helps you picture the actual size of the room. A standard moving box takes up about 0.05 m³, so if your whole household fits into boxes, a 2 m² (roughly 5 m³) unit already holds 100 perfectly stacked boxes.

	Area in m²	Volume in m³	Equivalent in wardrobes
Small cellar	1–1.5	3–5	1
A few pieces of furniture or boxes	2–2.5	5–8	5
1-room apartment (studio)	2.5–3.5	8–11	8
2-room apartment (1 bedroom)	3.5–5.5	11–15	11
3-room apartment (2 bedrooms)	5.5–8.5	15–25	15
4-room apartment (3 bedrooms)	8.5–15	25–35	25
5-room apartment or house	15–20	35–50	35

Why does the size of the storage unit matter?

The right storage unit depends on several factors: the number and type of items you want to store, and your own preferences. A unit that is too small turns into chaos and forces you to unpack half of it every time you need something from the back. A unit that is too large, on the other hand, drives up your costs for no reason — a self storage box in Germany costs €24,00 per m² per month on average, so every extra square metre shows up on the invoice. You can find the full breakdown in our guide to what a storage room costs in Germany.

The benefits of getting the size right

Choosing the right size has several advantages. By using the space efficiently you save money, because you only pay for what you actually use. On top of that, the right size lets you organise things properly and reach your belongings without having to empty half the unit first.

Step by step: calculating the perfect storage size

1. Take an inventory of your belongings

Start with an inventory of everything you want to store. Go room by room and note down all the larger items: furniture, appliances, sports equipment and anything else bulky. Also count the boxes or containers you plan to store.

2. Sort the items into categories

Group your things into categories to get a clearer picture. You can sort them by size, weight or how often you use them. This makes it much easier to estimate the space each group needs.

3. Think about access and organisation

When you calculate the space you need, think about how you will get to your things and organise them. If you need to reach certain items regularly, make sure there is enough room to move around comfortably — store those items near the door. Plan how you will stack, too: going upwards is the simplest way to gain square metres.

4. Calculate the space you need

Based on the previous steps you can now work out the size you need. Allow enough room for the whole household plus the space required to reach the things you use often. The table at the top of this article already gives you a solid starting point.

What to know about renting storage in Germany

Your Kellerabteil rarely covers it

Most German apartment buildings give each flat a Kellerabteil, a private cellar compartment, but these are usually only a few square metres and often already full of bikes, tyres and suitcases. For a full move or a renovation they fall short, so a rented unit normally complements the cellar rather than replacing it.

Notice periods create an overlap

German tenancies usually run on a three-month notice period, so a gap — or an overlap — between the old and the new flat is common, especially in tight city markets like Munich, Berlin and Frankfurt. If you are bridging a gap, size the unit for the whole household rather than a selection, and look for a provider with short notice periods so you are not tied in once you have moved.

Check whether the price includes VAT

Self storage is subject to VAT in Germany, currently 19%. Consumer offers are normally quoted gross, but business rates are often quoted net — so check which one you are looking at before you compare two providers, and before you decide that a slightly larger unit is out of budget.

Sperrmüll first, storage second

Before you book, remember that bulky-waste collection (Sperrmüll) is free or cheap in most German municipalities and usually needs to be booked a few weeks ahead. Getting rid of the wardrobe you will never reassemble often drops you a whole size category, which pays for itself every single month.

Finding the right storage unit

Once you know how much space you need, all that is left is to find an available storage unit near you in the right size. The best way to do that is storabble — the only independent comparison platform for storage space. Here is a quick overview of the most important cities:

Germany	More cities
– Storage in Berlin – Storage in Munich – Storage in Frankfurt	– Storage in Cologne – Storage in Stuttgart

Frequently asked questions