Splitting bills sounds simple until incomes differ, one room is bigger, or someone works from home all day. The right method is the one everyone agrees is fair before the first bill arrives. Here are the three common approaches, with examples.
The short version
- Agree on a method in writing before you move in or merge finances.
- Even splits are simplest; income-based splits are often fairer for couples.
- Use one shared account or app for bills so nobody is the “bank”.
Method 1: Split evenly
Each person pays the same share of every shared bill. It’s simple and works well for roommates with similar rooms and similar use of shared spaces.
Example
Three roommates share $2,250 rent, $180 utilities and $75 internet: $2,505 total. Each pays $835 a month.
Method 2: Split by income
Each person pays a share proportional to their income. This is common for couples, because an even split can leave the lower earner with little or nothing left while the higher earner saves easily.
| Partner A | Partner B | Total | |
|---|---|---|---|
| Take-home pay | $4,500 | $3,000 | $7,500 |
| Share of income | 60% | 40% | 100% |
| Rent ($2,000) | $1,200 | $800 | $2,000 |
| Utilities & internet ($300) | $180 | $120 | $300 |
| Left after shared bills | $3,120 | $2,080 |
Use take-home pay rather than gross pay if one person has much higher retirement contributions or health premiums.
Method 3: Split rent by room size, utilities evenly
For roommates, rent can be divided by bedroom square footage, with shared spaces split evenly. A common approach is to split half of the rent evenly (for shared spaces) and the other half by each bedroom’s share of total bedroom square footage. Add a little for a private bathroom or parking space if everyone agrees.
Example: three bedrooms
Rent is $2,400. Half ($1,200) is split evenly: $400 each. The other $1,200 is split by bedroom size: 180, 140 and 120 sq ft (440 total). Shares: 41%, 32%, 27%, or $491, $382 and $327. Totals: $891, $782 and $727.
Set up a simple system
- Write it down: which bills are shared, the split, due dates, and who pays each one.
- Use autopay from a shared account, or one person pays and everyone else reimburses by a set date each month.
- Track it in one place, whether that’s a shared spreadsheet or a bill-splitting app.
- Plan for changes: what happens if someone moves out, loses a job, or a bill spikes in winter?
Restaurants and one-off costs
For a dinner out or a one-time purchase, use the calculator below. It handles tax and tip and tells you who covers any leftover cents.
Once your share is settled, build the rest of your plan with our monthly budget guide, and look for savings on each shared bill in how to lower your monthly bills.
