How to use this calculator
Enter your total monthly rent and the number of people splitting it. Then choose a split method: equal (everyone pays the same) or by room size (each person pays proportionally based on their bedroom's square footage).
Equal splits are simpler and work well when rooms are similar. Proportional splits are fairer when there is a noticeable size difference -- a larger bedroom, a private bathroom, or better natural light.
Want to skip this math every single month?
ExpenDiv tracks each person's share and sends email reminders when rent is due. Your roommates never need to create an account.
Example: 3 roommates splitting $3,000/month
Alex has a 180 sq ft bedroom, Jordan has 140 sq ft, and Sam has 120 sq ft. Total: 440 sq ft.
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Alex: 180 / 440 = 40.9% of rent → $1,227/month
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Jordan: 140 / 440 = 31.8% of rent → $954/month
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Sam: 120 / 440 = 27.3% of rent → $818/month
With an equal split each would pay $1,000. Sam saves $182/month with the proportional method.
One-time calculation vs. ongoing tracking
This calculator tells you what each person owes. If you need to track rent every month -- sending reminders, recording who paid, and following up automatically -- ExpenDiv handles that ongoing work. Add your roommates once, set each person's share, and ExpenDiv emails them every month with your Venmo or CashApp link. No one needs to create an account.
How to split rent by income
Equal and room-size splits are the most common, but some households prefer to split rent proportionally by income -- the person who earns more pays more. Here is the formula:
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Add up all roommate incomes to get the household total
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Divide each person's income by the household total to get their percentage
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Multiply that percentage by the total monthly rent to get their share
Example: rent is $2,700. You earn $3,500, roommate A earns $2,500, roommate B earns $4,000. Household total: $10,000. Your share is 35% or $945. Roommate A pays 25% or $675. Roommate B pays 40% or $1,080.
Income-based splits require everyone to share what they earn, which some people find uncomfortable. They work best when there is a significant earnings gap and everyone agrees upfront that proportional contributions make sense. If the group is not comfortable with that conversation, room-size or equal splits are easier to agree on.
Frequently Asked Questions
How do you split rent fairly with roommates?
The two most common approaches are equal splitting (dividing total rent by the number of roommates) and proportional splitting by room size. Equal is simpler; proportional is fairer when rooms differ significantly in size or amenities.
How do you calculate rent based on room size?
Measure each bedroom in square feet. Divide each room's square footage by the total across all bedrooms to get each person's percentage of rent. Multiply that by total rent to get their share. The calculator above does this automatically.
Should roommates split rent equally or by room size?
If rooms are similar in size, equal splits are simpler and perceived as fair. If one room is noticeably larger or has a private bathroom, a proportional split by square footage tends to reduce long-term resentment.
How do I collect rent from roommates without the awkward ask?
Apps like ExpenDiv send automated email reminders when rent is due, with your payment link already in the email. Roommates never need to sign up or download anything.
How do I split rent when one roommate has a larger room?
Use the "By room size" method above. Enter each bedroom's square footage and the calculator assigns a proportional share. The person with the larger room pays more; the person with the smaller room pays less.
Does room square footage include shared spaces?
For proportional rent splitting, measure only the private bedrooms -- not the living room, kitchen, or shared bathrooms. Those shared spaces are already baked into the total rent everyone is splitting.
What if one room is smaller but has a private bathroom?
Square footage alone does not capture that. Agree on a manual premium for the private bathroom -- for example, add $75 to that person's share -- then run the proportional calculation on the remaining amount.
How do you split rent based on income?
Add up all roommate incomes to get the household total. Divide each person's income by the total to find their percentage. Multiply that by total rent. For example: rent is $3,000 and you earn $4,000 of a $10,000 household income -- your share is 40% or $1,200.
Is it fair to split rent by income?
It can be, but it requires everyone to disclose their earnings, which some find uncomfortable. Income-based splits make the most sense when there is a significant gap between roommate incomes and everyone agrees upfront. Equal or room-size splits avoid that conversation entirely.
How much rent should I pay if we split by income?
Your share = (your income / total household income) x total rent. If you earn $3,500 and your two roommates earn $2,500 and $4,000, the household total is $10,000. Your share is 35% of rent -- on a $2,700 lease, that is $945 per month.