Roommate Budget Split Calculator
Split rent and shared bills fairly between roommates by income instead of down the middle — so the share matches what each person can afford.
How it works
Total = rent + bills · By income: share = total × (person income ÷ combined income) · Even: share = total ÷ 2
The default 50/50 roommate split feels fair but hits a lower earner much harder as a share of their income. Splitting proportionally to income keeps housing at roughly the same percentage of pay for everyone, so no one is squeezed. The calculator shows both the dollar share and what that share represents against each person’s income, which is the number that actually reflects affordability.
Worked example
Rent of $2,400 plus $400 in bills is $2,800. If A earns $4,000 and B earns $3,000 (combined $7,000), A pays 2,800 × 4,000 ÷ 7,000 = $1,600 and B pays $1,200. Each is spending about 40% of income on housing, versus 35% and 47% under a flat 50/50 split.
Frequently asked questions
Is it fairer to split rent by income?
It depends on what you value. A 50/50 split treats the space as equally shared; an income-based split keeps the financial strain equal instead. Proportional splitting is common when roommates earn very different amounts, especially if bedrooms are similar in size.
What if we also have different room sizes?
You can combine methods: first weight the rent by room size, then split the shared bills by income. This calculator handles the income split; use a room-size split for the rent portion if bedrooms differ a lot.
Which bills count as shared?
Anything everyone uses jointly — electricity, gas, water, internet and streaming. Personal costs like a single roommate’s car or phone stay off the shared total.
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This calculator is for educational purposes. Double-check important results before acting on them.