How the Rent Increase Calculator works
This calculator applies a simple percentage-increase formula to your current rent, then translates the result into a dollar amount, a total cost over your new lease term, and — if you enter your income — a rent-to-income ratio you can compare against a well-known affordability guideline.
The formula
For a current monthly rent R and an increase percentage p, the new rent is:
New Rent = R × (1 + p / 100)
The dollar increase is simply New Rent − R. Multiplying that dollar increase by the number of months on the new lease gives the total added cost you will pay over the full lease term compared with staying at the old rent.
Worked example
Take a current rent of $1,500 with a 5% increase on a 12-month lease. The new rent is $1,500 × 1.05 = $1,575, a dollar increase of $75 per month. Over the 12-month lease, that adds up to $900 in extra rent compared with the old rate. If your monthly gross income is $5,000, the new rent-to-income ratio is $1,575 / $5,000 = 31.5% — just above the commonly cited 30% affordability threshold.
Reading the rent-to-income ratio
The 30% rule of thumb — associated with U.S. Department of Housing and Urban Development (HUD) housing standards — treats housing costs at or below 30% of gross income as generally affordable. Between roughly 30% and 50% is typically described as "rent-burdened," and above 50% as "severely rent-burdened." This is a general guideline, not a personalized recommendation: it ignores debt payments, savings goals, dependents, and local cost of living, all of which affect what a household can actually sustain.
What this calculator does not cover
- Legal caps on increases. Some states and cities limit how much or how often rent can be raised, and some exempt certain unit types. This tool performs only the percentage arithmetic and does not know your local rules.
- Notice requirements. Most jurisdictions require landlords to give written notice — commonly 30 to 60 days, though the exact period varies by location and lease type — before a rent increase takes effect. Verify the requirement that applies to your lease.
- Fees and utilities. If your total housing cost includes utilities, parking, or other fees billed separately from rent, add those before comparing the ratio to the 30% guideline.