You've found a rent split calculator—now what? This step-by-step guide walks you through exactly how to use one to calculate fair rent for you and your roommates.
We'll use Splitnow as our example, but these principles apply to any rent splitting tool.
Before You Start: What You'll Need
Gather this information before opening the calculator:
1. Total Monthly Rent
This is the full amount your landlord charges for the apartment. Include only the base rent—we'll handle utilities separately.
Example: $3,000/month
2. Total Square Footage
Find this in your lease, listing, or by measuring. This is the entire apartment, including common areas.
Example: 1,200 sq ft
3. Each Room's Square Footage
Measure each bedroom separately. Don't include closets unless they're walk-in closets you actually use as living space.
Example:
- Room A: 180 sq ft
- Room B: 150 sq ft
- Room C: 120 sq ft
4. Room Amenities
Note which rooms have special features:
- Private bathroom
- Walk-in closet
- Balcony or patio access
- Extra windows
- Higher floor (better views, less noise)
- Basement or ground floor
Step 1: Enter Basic Information
Start by entering your apartment's total rent and square footage.
Total Rent: Enter the monthly rent amount. Choose your currency if the calculator supports multiple currencies (USD, EUR, GBP, etc.).
Total Area: Enter the total square footage of the entire apartment. Select your unit (sq ft or m²).
This establishes the baseline for all calculations.
Why Total Square Footage Matters
The calculator uses total square footage to determine what portion is common space (living room, kitchen, hallways) versus private space (bedrooms). Common areas are split equally; private space is divided based on room size.
Example:
- Total apartment: 1,200 sq ft
- Total bedrooms: 450 sq ft (180 + 150 + 120)
- Common areas: 750 sq ft
Step 2: Add Each Room
Click "Add Room" for each bedroom in the apartment.
For each room, enter:
Room Name (Optional)
Give each room a name to keep track. This could be:
- "Master Bedroom"
- "Room A"
- The person's name: "Alex's Room"
Room Size
Enter the square footage of just the bedroom, not including shared spaces.
Tip: If you don't have exact measurements, estimate using standard room sizes:
- Small bedroom: 100-120 sq ft
- Average bedroom: 130-160 sq ft
- Large/master bedroom: 170-220 sq ft
Basic Amenities
Check the boxes for any amenities the room has:
- Private Bath: The room has its own bathroom that other roommates don't use
- Walk-in Closet: A closet large enough to walk into
- Balcony: Direct access to a balcony or patio
These add a percentage bonus to the room's base rent.
Step 3: Configure Advanced Options (Optional)
Most calculators let you fine-tune the calculation. In Splitnow, expand "More Options" for each room to set:
Window Count
How many windows does the room have? More windows typically means better natural light and ventilation.
Floor Level
- Basement: Usually discounted due to less light, potential moisture
- Ground floor: Standard pricing
- Upper floor: Often premium due to better views, less street noise
Natural Light
- Low: Few or small windows, faces another building
- Medium: Average light
- High: Large windows, great sun exposure
Noise Level
- Quiet: Away from street, interior unit
- Normal: Average noise
- Noisy: Faces busy street, near elevator
Preset Price (Special Cases)
If a room has a pre-agreed price (like a couple paying a fixed amount), enter it here. The calculator will adjust other rooms accordingly.
Step 4: Review Calculation Settings
Before calculating, check the weighting settings. These determine how much each factor affects the final price.
Default Weights
Most calculators use sensible defaults:
- Square footage weight: 70%
- Private bathroom bonus: 10%
- Balcony bonus: 5%
- Walk-in closet bonus: 3%
- Each window bonus: 2%
- Floor level adjustment: 5%
- Natural light bonus: 5%
- Quiet bonus: 5%
Adjusting Weights
If your roommates feel strongly that certain factors matter more or less, adjust the weights before calculating. For example:
- In a noisy city, you might increase the quiet bonus to 10%
- If no one cares about closets, reduce that bonus to 0%
Pro tip: Agree on weights before running the calculation. It's easier to agree on how factors should be weighted than to argue about the final numbers.
Step 5: Calculate and Review Results
Click "Calculate Split" to see the results.
What You'll See
Each room displays:
- Room name
- Monthly rent amount
- Percentage of total rent
- Key amenities summary
Example Results
For a $3,000/month apartment with three rooms:
| Room | Size | Amenities | Monthly Rent |
|---|---|---|---|
| Master (Room A) | 180 sq ft | Private bath, 3 windows | $1,180 |
| Room B | 150 sq ft | 2 windows | $980 |
| Room C | 120 sq ft | 1 window, basement | $840 |
| Total | $3,000 |
Understanding the Breakdown
The summary section shows:
- Common area share: How much each person pays for shared spaces (equal for everyone)
- Private space cost: Based on room size and amenities
- Adjustments: Bonuses or discounts for amenities
Ready to split your rent fairly?
Use our free calculator to find the perfect rent split based on room size, amenities, and more.
Try the CalculatorStep 6: Share With Roommates
The most important step: sharing the results so everyone sees the same calculation.
Copy the Share Link
Click "Share Link" to copy a URL that includes all your inputs. When roommates open this link, they'll see exactly what you see—same rooms, same amenities, same calculation.
Why This Matters
Sharing a link from a neutral calculator removes the awkwardness of proposing numbers yourself. Instead of saying "I think I should pay $840," you're saying "Here's what the calculator suggests based on our room sizes."
Other Sharing Options
- Copy Text: Get a plain-text summary to paste into a group chat
- Save PDF: Download a document for your records (useful to attach to a roommate agreement)
Step 7: Discuss and Adjust
Once everyone reviews the calculation:
If Everyone Agrees
Great! Save the PDF and add the amounts to your roommate agreement.
If Someone Disagrees
Don't panic. Common adjustments include:
- Reconsider amenity weights: Maybe the private bathroom should be worth 15% instead of 10%
- Verify measurements: Remeasure rooms if sizes seem off
- Factor in something the calculator missed: Maybe one room has a radiator that makes it hot in summer
Run the calculation again with adjusted inputs until everyone feels the split is fair.
Common Questions
What if I don't know the exact square footage?
Estimate using the floor plan or by pacing off the room (one pace ≈ 2.5-3 feet). Even rough estimates produce more fair results than equal splits.
Should I include closet space?
Standard closets: No, don't include them in room size. Walk-in closets: If they're large enough to be usable space, either include them in square footage OR check the "walk-in closet" amenity—not both.
What about rooms that share a bathroom?
If two rooms share a bathroom and no room has a private bath, the calculator handles this automatically—no one gets a bathroom bonus.
How do I handle a couple sharing a room?
Option 1: Use the "Preset Price" feature to set their room at 1.3-1.5x what a single person would pay. Option 2: Calculate as normal, then have the couple add 30-50% to their share for increased common area usage.
Can I save my calculation for later?
Yes! Bookmark the share link or save the PDF. You can also use the "Save Scenario" feature to store calculations for comparison.
Tips for the Smoothest Process
1. Do It Together
Consider filling out the calculator as a group when touring the apartment or on move-in day. Real-time collaboration prevents anyone from feeling like they're being handed a predetermined number.
2. Use the "Start Over" Feature
If your first attempt gets too complicated, reset and start fresh. Sometimes a clean slate helps.
3. Round to Clean Numbers
If the calculator says $847.23, it's usually fine to round to $850. Small adjustments for convenience won't cause problems.
4. Document Everything
Once agreed, save the PDF and reference it in your roommate agreement. This prevents "I thought we agreed on $800" arguments later.
Ready to Try It?
Using a rent split calculator takes the guesswork and awkwardness out of dividing rent. In just a few minutes, you can have a fair, transparent split that everyone can agree on.
Open the calculator, enter your apartment details, and share the results with your roommates today.