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Rent increase calculator

Enter your rent and the 12-month change of the index in your lease. The calculator shows the new rent, how much more you pay per month and per year, and what a counteroffer cap would save.

Educational simulation. Not investment advice. Results are estimates based on the data you enter and do not replace advice from a qualified professional.

Reviewed on Nov 1, 2026
Your rent
Counteroffer

Use the index and the anniversary date written in your lease. Local rent control rules may cap increases; check them.

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—New rent
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Your rent with the index and with the cap

Current rent, new rent with the full index increase and new rent with your cap.

Tap the chart to see the values.

If the same increase repeats

Rent year by year with the index rate and with the cap, and the extra you would pay.

Tap the chart to see the values.

Year by year

Next step

Take this page’s results to another calculator with the fields already filled in.

The summary lists your inputs, results, formulas, assumptions and sources. The full report also includes the charts and interpretations, in color. In the print dialog, choose Save as PDF.

Method, assumptions and sources

Formulas

Index factor = 1 + 12-month index change (entered as a yearly rate)
New rent = current rent × factor (with the box checked, the factor is at least 1)
Counteroffer = current rent × [1 + min(increase, cap)]
Projection: rent in year k = current rent × (1 + increase)^k

Assumptions and limits

  • The same increase is applied to the whole year; the projection repeats it every year only to show the order of magnitude.
  • Local rent control rules, notice periods and lease clauses (floors, caps, fixed steps) are not included: check them.
  • Does not include utilities, fees or property taxes billed with the rent.

Official sources and references

Frequently asked questions

How is a rent increase calculated?

Multiply the current rent by (1 + the 12-month change of the index named in the lease), or by the fixed percentage in the escalation clause. Enter that change, and the calculator shows the new rent, the increase per month and per year, and the result with your counteroffer cap.

How do I read the default example?

A $2,000 rent with a 3% index change becomes $2,060: $60 more a month and $720 more over 12 months. With a 2.5% cap, the counteroffer would be $2,050, saving $10 a month. If the same increases repeat for 5 years, the rent reaches about $2,319 with the index and $2,263 with the cap.

Which index applies?

The one written in the lease, most often the consumer price index (CPI) for the area, sometimes a fixed percentage. Use the change over the 12 months before the anniversary date, as published by the statistics office.

What if the index falls?

Applying a negative change lowers the rent. Many leases keep the rent unchanged instead; check the box to match your lease.

Can I negotiate a lower increase?

Often, yes. The index is the most the lease allows, and replacing a reliable tenant costs a landlord vacancy, cleaning and listing fees. Propose a cap with the numbers from this page and put any agreement in writing.

Are there legal limits?

Some cities and states have rent control or rent stabilization rules that cap increases or require advance notice. This calculator does not include local rules, so check them for your property.

When should I get help?

If the increase does not follow the lease, or you are unsure about a clause, talk to the property manager, a tenant association or a lawyer. This calculator is an educational tool and does not replace reading the lease.

Rent increase: how to work out the new rent

Most leases with an escalation clause raise the rent once a year by the change in a price index, usually the consumer price index (CPI), or by a fixed percentage. The increase applies from the lease anniversary and uses the index change over the previous 12 months.

The math

New rent = current rent × (1 + 12-month index change). With a $2,000 rent and a 3% increase, the new rent is $2,060, or $60 more a month and $720 more over the year.

$2,000 rentIncreaseNew rent
Index up 3%3.0%$2,060.00
Cap of 2.5%2.5%$2,050.00
Index down 1%−1.0%$1,980.00, or $2,000.00 if the lease keeps the rent

Negotiating with a cap

The index sets what the lease allows, not what both sides must accept at renewal. Tenants with a good payment record often propose a cap close to general inflation, and many landlords accept it to avoid vacancy and turnover costs. Put any agreement in writing as an amendment to the lease.

Small differences compound

A 0.5-point difference looks small in one year, but if it repeats it adds up over a long lease. The projection chart repeats the same increase every year to show the order of magnitude.

Check local rules

Some cities and states limit how much and how often rent can rise, or require written notice before an increase. Check the rules where the property is located and the exact wording of your lease.