1. Use the same kind of income for everyone
Take-home pay is the most common choice because it is what you actually have to spend. Before-tax works too, as long as every person uses the same measure.
Free calculator
Split bills by income calculator for couples and roommates
When one person earns a lot more, splitting every bill 50/50 can leave the other with almost nothing left. Enter each person's income and who pays which bill today, and see each fair share by income, how far off you are now, and the single transfer that evens it up each month.
Split bills by income calculator
Runs in your browser. Nothing is sent or saved. Enter each person's monthly income (before or after tax, just use the same for everyone), then the shared bills and who pays each one.
People and monthly income
Shared monthly bills
Shared bills per month
2600.00
Combined monthly income
6500.00
| Person | Share | Fair amount | Pays now | Difference | Left of income |
|---|---|---|---|---|---|
| Alex | 61.5% | 1600.00 | 1800.00 | +200.00 | 2400.00 |
| Sam | 38.5% | 1000.00 | 800.00 | -200.00 | 1500.00 |
To even up each month
- Sam sends Alex 200.00
How it works: each person's share is their income divided by combined income (or an equal share in even mode). Fair amount is total shared bills times that share. Difference is what they pay now minus their fair amount, and the transfers settle the differences with as few payments as possible. A planning aid, not financial advice.
How to split bills by income, step by step
2. List only the truly shared bills
Rent, utilities, wifi, shared groceries and household supplies usually count. Personal phone plans, gym memberships, debt payments and hobbies stay with each person.
3. Note who pays each bill today
Most couples and flats already have one person on the lease and another on the energy account. You do not need to move accounts around; the calculator works out the difference.
4. Settle the difference with one transfer
Instead of splitting every bill, the person who pays less than their share sends one transfer a month to whoever pays more. One payment, on a fixed day, is easy to keep up.
5. Revisit when income or bills change
A raise, a new job, a rent increase or a new roommate all change the fair split. Re-run the numbers and agree the new amount before the next month starts.
Choosing a place together? The rent affordability calculator shows what rent your combined income supports. For flatmates who split by room instead, use the rent split calculator and put the rules in the free roommate bill agreement template.
Questions
How do you split bills by income?
Add up everyone's monthly income and work out each person's percentage of the total. Each person then covers that percentage of the shared bills. If one person earns 4,000 and the other 2,500, they cover about 62% and 38% of shared costs.
Is splitting bills by income fairer than 50/50?
It depends on what you both agree feels fair. A 50/50 split is simple but can leave the lower earner with very little left each month. An income-based split means everyone gives up a similar share of their pay. Compare both in the calculator before you decide.
Should we use take-home pay or gross income?
Take-home pay is more common because it reflects what each person can actually spend. Either works if everyone uses the same measure.
Does splitting by income work for roommates, not just couples?
Yes, if everyone agrees. It is more common for couples, but some flats split shared costs by income when earnings are very different. Roommates often split rent by room size and utilities evenly instead; the rent split calculator covers that.
How do we keep track of who paid what each month?
Log each shared bill with who paid it and everyone's share, then settle on a fixed day. IPaid does this free for one shared home: add the bill, set the shares, and everyone sees what they owe without a spreadsheet.
More from Don't Work Free