3 min read · Updated 2026-10-28

Split Bills by Income: A Partner Expense Calculator in Google Sheets

Splitting everything 50/50 is simple, but it can feel unfair when one partner earns a lot more. A common alternative is to split shared bills in proportion to income, so each person contributes the same share of their pay. Here is how to set it up in Google Sheets in about ten minutes.

Step 1: Enter take-home income

In A2 type your name and in B2 your monthly take-home pay (after tax). In A3 and B3 do the same for your partner. Use take-home, not salary, so the percentages reflect what each person actually has available.

Step 2: Calculate each person's share

In C2 type =B2/SUM($B$2:$B$3) and copy it down to C3. Format the column as a percentage. If you take home $4,200 and your partner takes home $2,800, the shares are 60% and 40%.

Step 3: List the shared bills

On a second tab, list rent or mortgage, utilities, internet, groceries, insurance and anything else you both use, with a monthly amount for each. Add a total at the bottom, for example in B10: =SUM(B2:B9).

Step 4: Work out what each person owes

Back on the first tab in D2 type =C2*Bills!$B$10 (change Bills to your tab name). With $2,500 of shared bills, the 60% earner owes $1,500 and the 40% earner owes $1,000.

Step 5: Settle up when one person pays more than their share

Add a column E for what each person actually paid this month, then in F2 use =D2-E2. A positive number is what that person still owes; a negative number is what they are owed. The two numbers always cancel out, so you can send one transfer and be done.

Options that keep it fair

• Hybrid split: divide rent 50/50 because you both need somewhere to live, and split groceries by income.
• Personal money first: give each person the same fixed amount of spending money before splitting anything.
• Review twice a year: recalculate whenever either income changes.

There is no single right method, so agree the rule together before you build the sheet. If one or both of you has ADHD, our guide to budgeting as a couple with ADHD covers money dates and shared roles. For more on agreeing a system as a team, see our guide to making a budget in Google Sheets.

Want it ready-made?

The GridX Couples Budget Planner handles shared and personal money for two in Google Sheets and Excel. See the Etsy listing.

Frequently asked questions

How do you split bills proportionally to income?

Divide each person's take-home pay by the combined take-home pay to get their percentage, then multiply that percentage by the total shared bills.

Should I use gross or take-home pay?

Use take-home pay after tax. It reflects the money each person can actually spend, so the split matches reality.

Is splitting by income fairer than 50/50?

Many couples find it fairer when incomes differ a lot, but it depends on what you both agree. Some couples mix methods, such as 50/50 rent and income-based groceries.

Related guides

• Budgeting as a Couple When One or Both of You Have ADHD
• Wedding Budget: Track Who Pays for What in a Spreadsheet
• How to Make a Budget in Google Sheets (Step by Step)

Planner that goes with this guide: Couples Budget Planner. All guides