Rent Increase Calculator
Work out a rent increase as a percentage, or prorated rent for a partial first or last month.
About the Rent Increase Calculator
A rent increase percentage is the change divided by the old rent. Prorated rent charges only for the days occupied, and there are three common ways to work out the daily rate: rent ÷ days in that month, rent × 12 ÷ 365, or rent ÷ 30. They give slightly different answers, so leases usually say which applies. Many places cap rent increases or require notice: for example, California's statewide cap is 5% plus inflation (maximum 10%) per year for covered units.
The formula
Increase % = (new − old) ÷ old × 100; prorated = daily rate × days occupied
Worked example
Example: Increase = 4.55%
- Inputs: Calculate: Rent increase; Current monthly rent: $2,200; New monthly rent: $2,300.
- Formula: Increase % = (new − old) ÷ old × 100; prorated = daily rate × days occupied
- Result: Increase = 4.55%
Questions people ask
Do I count the move-in day?
Usually yes; this includes it.
Is a 10% increase legal?
It depends on local law and your lease; many cities and states cap increases.