What the rent-to-income ratio is
The rent-to-income ratio is the percentage of a tenant's gross monthly income that goes to rent. Landlords use it to screen affordability before running credit and background checks; renters use it to sanity-check a budget.
The formula is simple: rent ÷ gross monthly income × 100. Gross means income before taxes — that's the standard used in screening.
The 30% rule and the 3× rule
Two benchmarks show up everywhere. The 30% rule says rent should be no more than 30% of gross monthly income. The 3× rule is the same idea from the other side: the tenant should earn at least three times the rent.
Example: a tenant earns $5,000/month and rent is $1,500. That's $1,500 ÷ $5,000 × 100 = 30% — right at the line, and they earn exactly 3× the rent.
How to read your result
At or below 30% is generally considered affordable. Above it, the tenant is more stretched — not automatically a no, but worth a closer look at the rest of the application. The calculator also shows the max rent that fits the 30% rule for that income, which is handy when you're setting a price rather than screening a tenant.
Price it against the real market
Affordability is only half the question — the other half is whether your rent matches the market. Get a free rent estimate for any address to anchor the number, and read what the rent-to-income ratio means for more context.