ManaWGOpen the appSplit flat-share rent by room size
When the rooms in a shared flat (WG) are different sizes, an equal rent share rarely fits. The calculator splits the rent by the floor area of each room and spreads the shared rooms equally across everyone. The result is a proposal that you still need to agree on.
By Abubakar Abditube (ManaWG) · Published · Updated
Calculator
Enter the rent, the area of each room in square metres and the area of the shared rooms such as the kitchen, bathroom and hallway. Whether you use Kaltmiete (rent excluding utilities) or Warmmiete (rent including heating and other utilities) is up to you; the calculation stays the same. The pre-filled values are an example. What you enter stays in your browser and is neither stored nor sent anywhere.
| Room | Area | Monthly rent |
|---|---|---|
| Room 1 | 12 m² | €225.00 |
| Room 2 | 18 m² | €300.00 |
| Room 3 | 24 m² | €375.00 |
| Total | €900.00 |
The formula with an example
Each room pays according to its area, and the shared area is spread equally across all people. As a formula: share = rent × (room area + shared area ÷ number of people) ÷ (sum of all room areas + shared area). Example: €900.00 rent, three rooms of 12, 18 and 24 m² and 18 m² of shared area. Each room is credited with 6 m² and then counts as 18, 24 and 30 m², 72 m² in total. Amounts are rounded to the cent so that the shares add up to exactly the rent. Other models, such as equal shares or mixed splits, are covered in how to split flat costs fairly.
Example: €900.00 rent split by room size
| Room | Area | Share without shared area | Share with 18 m² shared area |
|---|---|---|---|
| Room 1 | 12 m² | €200.00 | €225.00 |
| Room 2 | 18 m² | €300.00 | €300.00 |
| Room 3 | 24 m² | €400.00 | €375.00 |
| Total | 54 m² | €900.00 | €900.00 |
Without shared area, each room pays only for its own area. With it, the gap between large and small rooms gets smaller.
Surcharges: balcony, private bathroom, sloping ceiling
The area formula only knows square metres. A balcony, a private bathroom or a sloping ceiling make a room worth more or less, but there is no fixed rate and no usual percentage. It is a matter of agreement within the flat. Settle on a fixed monthly amount in euros. To make the total add up, deduct a surcharge from the rent first, split the rest by area, then add the surcharge to that person’s share. For a discount, work the other way round. For a sloping ceiling, it is best to measure the area you can actually use.
Utilities, electricity and internet
Enter the rent you want to split by area in the calculator. With Warmmiete, the advance payment for Nebenkosten (utility and service charges) is already part of the result. Flat shares usually split electricity and internet equally, because everyone uses them. How that works and what applies to back payments is covered in utilities and internet in a flat share.
Using the result in ManaWG
Set the rent up as a fixed cost in shared expenses: enter the amount, choose an interval of one month, and under “Paid by” pick the person who transfers the rent to the landlord. Under the split, choose “Manually” and enter each person’s amount from the calculator. ManaWG shows whether the shares add up to the rent. Splitting by percentage is not available; you enter euro amounts. After that, the app books the rent as an expense every month automatically.
Frequently asked questions
What if a room has a balcony?
There is no fixed rate. Agree on an amount in euros that this person pays extra, and work it out of the rent as described above. Put the agreement in writing.
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