Splitting by room size is a common way to keep shared housing fair. Shared spaces are split equally.
How to use the Rent Split Calculator
- Total rent
- Your room size
- All bedrooms combined
- Number of roommates
- Share of rent for common areas
Results update as you type, and every field accepts the units shown in its menu.
How it works
Part of the rent covers shared areas and is split equally; the rest is split by bedroom area.
Tips
- Use the figures from your own bills and product labels – prices and appliance ratings vary widely.
- Look at yearly totals: small daily costs add up and make it easier to compare options.
- Round quantities up to whole packs, rolls or bulbs when you shop.
- Re-check the numbers when prices change; most results scale directly with the unit price.
Common mistakes to avoid
- Confusing watts (power) with watt-hours or kilowatt-hours (energy).
- Comparing prices without bringing them to the same unit first.
- Ignoring one-off costs such as installation, delivery or replacement parts.
Inputs explained
| Field | What to enter |
|---|---|
| Total rent | Amount in your currency |
| Your room size | Units: m², ft², cm², in², yd², acre … |
| All bedrooms combined | Units: m², ft², cm², in², yd², acre … |
| Number of roommates | A number |
| Share of rent for common areas | In % |
What each result means
- Your share = [Total rent]×([Share of rent for common areas]÷100÷[Number of roommates] + (1 – [Share of rent for common areas]÷100)×[Your room size]÷[All bedrooms combined])
- Equal split = [Total rent]÷[Number of roommates]
Example values
How the main result changes when Total rent changes and everything else stays at the example values above:
| Total rent | Your share |
|---|---|
| 1,200 | 440 |
| 1,800 | 660 |
| 2,400 | 880 |
| 3,000 | 1,100 |
| 3,600 | 1,320 |
| 4,800 | 1,760 |
Formula
Share = rent × (shared share ÷ people + private share × room area ÷ total room area)Worked example
Inputs — Total rent: $2,400; Your room size: 14 m²; All bedrooms combined: 36 m²; Number of roommates: 3; Share of rent for common areas: 40 %.
Results — Your share = $880.00; Equal split = $800.00.
Frequently asked questions
What share for common areas?
Many groups use 30–50%; agree on it together.
Should private bathrooms count?
Add a premium for en-suite rooms if everyone agrees.
What formula does the Rent Split Calculator use?
Share = rent × (shared share ÷ people + private share × room area ÷ total room area).