Rent increase calculator
Turn a percentage into a monthly amount—or work backward from a proposed rent. See the difference over a full year.
Compare your monthly rent
New monthly rent
$1,890.00
5% increase from your current rent
$90.00 more each month. Both bars use the same dollar scale.
The annual difference assumes 12 months at the new rate. This tool calculates the change; it does not establish whether the increase is permitted.
See both sides of the increase
A percentage describes the size of a change relative to your current rent. A dollar amount tells you how much more or less to budget each month. This calculator keeps both visible, whether you start with a percentage, a dollar change or the proposed new monthly rent.
Switching the calculation mode converts the current result into the new input type. For example, a 5% change on $1,800 becomes a $90 change, or a proposed monthly rent of $1,890.
The formulas
New rent = current rent × (1 + percentage ÷ 100)
Percentage = (new rent − current rent) ÷ current rent × 100
12-month difference = (new rent − current rent) × 12
The 12-month result assumes the change applies to all 12 months. If a new rate begins partway through your budgeting year, multiply the monthly difference by the number of months affected instead. Use the prorated rent calculator separately if your agreement calls for a partial-month calculation.
Worked example: a $75 change
For hypothetical current rent of $1,500 and a proposed increase of $75, new rent is $1,575. The percentage change is $75 ÷ $1,500 × 100 = 5%. Over 12 months, the added cost is $75 × 12 = $900.
If the same $75 is added to $2,000 rent, the percentage is 3.75%. The dollar change is identical, but its size relative to the starting amount is different. Always use the old rent as the denominator when describing an increase.
Keep the calculation separate from the rules
A calculated percentage does not establish whether a rent change is permitted. Before acting, identify the terms of your agreement and consult the relevant official resources for your location. The USAGov tenant-rights page provides a starting point. No jurisdiction-specific caps or notice requirements are assumed here.
Questions, answered
How do I calculate the percentage increase between two rents?
Subtract current rent from new rent, divide the difference by current rent, then multiply by 100. The current rent must be greater than zero. For $1,800 increasing to $1,890, the result is 5%.
Can I calculate a rent reduction?
Yes. Enter a negative percentage or dollar change, or a new rent below the current rent. The calculator accepts reductions down to zero rent and rejects changes that would make rent negative.
Does the calculator tell me the maximum legal increase?
No. It calculates arithmetic only. It has no location, property exemption, notice-period or rent-regulation data. Use your lease and current local official resources to assess what applies.
Sources & calculation notes
As of October 25, 2026. Numerical examples are hypothetical calculations using our published formulas and conventions, not quotes or legal limits.
- USAGov: Tenant rights — Starting point for finding state tenant-rights and complaint resources. This calculator does not determine legal obligations.
- U.S. Naval Observatory: Calendars — Background on the Gregorian calendar. Our date arithmetic uses Gregorian month lengths and leap years.