Rent & Mortgage Split Calculator

Financial experts often recommend the "28/36 rule," which suggests that you shouldn't spend more than 28% of your gross monthly income on housing expenses (mortgage principal, interest, taxes, and insurance), and no more than 36% on total debt (including car loans, student loans, etc.).

Most affordability rules (like the 28% rule) use gross income. However, using net (take-home) pay gives a much more realistic picture of how the mortgage will feel in your daily budget. Whichever you choose, ensure you use the same method for both partners.

If one partner is providing the entire down payment, you might want to adjust the monthly split to compensate, or draft an agreement on how equity is shared if you ever sell the home. This calculator focuses purely on the monthly cash flow burden.

A proportional split should adapt as your careers grow. It's a great practice to revisit your mortgage split whenever there's a significant income change for either partner. A quick check-in every year can ensure your arrangement still feels fair.

The fairest approach for most couples is proportional splitting based on income. Calculate what percentage each partner earns of the total household income, then apply those same percentages to rent. This ensures both partners contribute equally relative to what they earn. For example, if you earn $5,000/month and your partner earns $3,000/month, you'd pay 62.5% and they'd pay 37.5% of rent.

Financial experts recommend spending no more than 30% of your combined gross income on housing. For a couple earning $8,000/month combined, that means a maximum rent of $2,400. But look at it from each partner's perspective too. If a proportional split means one partner is spending 40% of their individual income on rent, the apartment may be too expensive for your situation.

In most cases, no. When there's a significant income gap, a 50/50 split means the lower earner spends a much larger percentage of their paycheck on housing. This can lead to financial stress, resentment, and an imbalance in the relationship. Proportional splitting ensures both partners feel the same level of financial impact from housing costs.

If both names are on the mortgage, you're both legally responsible for payments regardless of your relationship status. Options include selling the property and splitting equity, one partner buying the other out (requires refinancing), or continuing to co-own with a written agreement. If you're unmarried, consider a cohabitation agreement before buying together. This calculator helps you understand the financial commitment before you sign.

Enter both incomes into the calculator above and it calculates a proportional split. The partner earning more pays a proportionally larger share of the rent. Most couples find this feels fairer than splitting 50/50 when there's a salary gap.

It depends on your household situation. If both spouses earn similar salaries, 50/50 works fine. If there's a significant income gap, splitting by income ratio means neither partner is financially strained. Use this calculator to see both options.