Rent Affordability Calculator

Rent affordability guidelines suggest that housing costs should not exceed 30% of gross income (the classic 30% rule). In many UK cities, renters spend significantly more — London renters average over 40% of income on rent

The calculator uses the standard published formula for rent affordability. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, percentages. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: 30% rule: max monthly rent = (annual take-home / 12) × 0.30. Each step in the calculation is shown so you can verify the result manually.