Rent Split Calculator
The roof, divided — the even split, the by-income split that corrects it, and your share set against HUD's 30% cost-burden line.
Rent Split Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Two-tier income model — one share for you, one common share for the rest
- Rent 100 to 50,000; incomes 100 to 100,000
In short: $2,400.00 split 3 ways is $800.00 each; with even incomes the by-income split agrees, and your share sits at 17.8% of a $4,500 month — under HUD's 30% line. Uneven incomes are where the even split starts lying, one roommate at a time.
Formula
even = rent ÷ people; yours = rent × your income ÷ total income; line = yours ÷ your income
Two honest ways to split one roof. The even split divides by heads and is fair when incomes are fair. The by-income split divides the rent in proportion to what comes in the door — the correction that stops the lowest earner from subsidizing the highest. The line card holds your share against HUD's standard: over 30% of income spent on housing is cost-burdened, over 50% severely so.
Worked Example
- Enter the rent and the people on the lease.
- Enter your income and theirs, per month.
- Read the even split, the by-income split, and your burden line.
Defaults: $2,400.00, 3 people, $4,500 in and $4,500 in — $800.00 each either way, your line at 17.8% of income, under the 30% mark.
Strengths & Limits Of This Model
Where this engine is strong
- Even AND by-income, priced side by side
- HUD's 30% and 50% lines applied to YOUR share
- The even split's subsidy made explicit
Where it stops
- One income step — fully individual shares need a run per person
Practical Use Cases
New leases
set shares before the deposit
Raise season
re-split when incomes change
The 30% check
is this roof even legal for you
Methodology & Editorial Standards
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Rent Split Calculator — 8 Expert FAQs
8 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How should rent be split between roommates?
Two honest ways: evenly, by heads, or by income — each person pays rent in proportion to what they earn. Even is fair when incomes are similar; by-income is the correction when they are not, and this page prices both so the difference is a number, not an argument.
What is the 30% rule?
HUD's standard: a household paying more than 30% of gross income on housing is cost-burdened, and more than 50% severely so. The line card holds YOUR share of the rent against that threshold — the split can be even and the roof still be too heavy for you.
Should I use gross or net income?
The 30% line is stated in gross, but you pay rent from net. The page prices whatever you enter — enter net for the honest picture and treat 30% as generous, enter gross to match HUD's books.
What if the rooms are not equal?
Price the difference explicitly: agree the even split first, then move dollars — say $100 a month — from the small room to the large one until the holders call it fair. Baking the premium into a silent split is how resentments get leased year to year.
What is the 40x rule?
Landlords' screen: your yearly income should be about 40 times the monthly rent. On $2,400.00 that is $96,000 a year across the household — which is why guarantees and co-signers exist, and why the by-income split matters for who actually carries the paper.
Do utilities split the same way?
Bills ride on usage, not salary — the even split with corrections. The roommate bill split page prices the shared stack and the IOU if one of you fronts it; the utility bill split page prorates an account by the days each of you was actually in the house.
What if someone has no income for a month?
The by-income split needs every share above zero to resolve, so enter their realistic income — savings, support, whatever carries the month — and settle the difference outside the lease. A zero on this page is a guard, not a judgment.
Does a by-income split survive a raise?
Only until the next one — re-split when incomes move by a meaningful step, and put the trigger in writing when you sign. The page prices the correction instantly: enter the new incomes and read the new shares before the conversation, not during it.