Brazil rent adjustment (reajuste de aluguel) calculator

The new rent after 12 months, with your contract’s index and the months that go into the calculation.

New rent

R$2,066.97

3.35% in 12 months, from Oct/2025 to Sep/2026

+R$66.97 a month
+R$803.61 a year
IGP-M

Your rent of R$2,000.00 goes up to R$2,066.97 at the October 2026 adjustment: the IGP-M accumulated 3.35% from October 2025 to September 2026.

The calculation multiplies the factors (1 + the month’s change) of the 12 months; the result is 1.0335. The Central Bank data were read on October 6, 2026.

Check the index, the base month and the calculation period in the contract: some contracts use another 12-month interval.
The adjustment can only be annual: a clause with a period shorter than a year is void (Law 10.192/2001, art. 2, § 1).

The new rent

Current rentR$2,00097%
IncreaseR$673%

I’m not an accountant or a financial advisor. This is an estimate, for information only. Check with a professional before you decide.

Your numbers

example: change the numbers

Current rent, per month

The rent itself, without condominium fees, property tax (IPTU) and other charges.

Contract index

The index written in the adjustment clause of your contract. The IGP-M and the IGP-DI are from the FGV; the IPCA and the INPC, from the IBGE.

IGP-MFGV, the most commonIPCAIBGE, the official inflationINPCIBGE, lower-income familiesIGP-DIFGV, closed month

Month of the adjustment

The month the contract has its anniversary, that is, when the new amount takes effect.

Year of the adjustment

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The months in the calculation

Month	Change in the month	Cumulative
Oct/2025	-0.36%	-0.36%
Nov/2025	0.27%	-0.09%
Dec/2025	-0.01%	-0.10%
Jan/2026	0.41%	0.31%
Feb/2026	-0.73%	-0.42%
Mar/2026	0.52%	0.09%
Apr/2026	2.73%	2.83%
May/2026	0.84%	3.69%
Jun/2026	-0.50%	3.17%
Jul/2026	-1.16%	1.98%
Aug/2026	-0.22%	1.75%
Sep/2026	1.57%	3.35%

How it works

Residential rent can only be adjusted once a year: a clause with a period shorter than a year is void (Law 10.192/2001, art. 2, § 1). The index is not set by law: what the contract says applies, as long as it is not the exchange-rate change or the minimum wage (Law 8.245/1991, art. 17). The most used are the IGP-M and the IGP-DI, from the FGV, and the IPCA and the INPC, from the IBGE.
The calculator accumulates the index’s monthly changes over the 12 months before the adjustment month: it multiplies the factors (1 + the month’s change) and applies the result to the current rent. For an adjustment in October 2026, the months are October 2025 to September 2026.
The monthly changes come from the Central Bank of Brazil API (series 189, 433, 188 and 190), with two decimal places. That is why the accumulated figure can differ by hundredths from the number published by the FGV or the IBGE, which is calculated on the index numbers.

Worked example

A rent of R$2,000.00 adjusted in January 2026 by the IPCA: the index accumulated 4.26% from January to December 2025 (factor 1.0426), and the new rent is R$2,085.29, that is, R$85.29 more per month and R$1,023.45 per year.

Sources

Text checked on October 6, 2026

Good to know

What counts is the contract: the index, the base month and the calculation period are in the adjustment clause. Without a clause, the rent does not rise by itself: an agreement is needed (Law 8.245/1991, art. 18) or, after three years, judicial review (art. 19).
The calculator uses the 12 monthly changes before the adjustment month. Some contracts use another interval or another base month: check the clause.
The indices go up to the last month the Central Bank released on the reading date. For a newer month, the calculator warns that data are missing.
When the cumulative index is negative, the calculator shows the calculation, but the rent only goes down if the contract or an agreement provides for it.
Condominium fees, property tax (IPTU) and other expenses do not go into the calculation; they follow their own rules (Law 8.245/1991, arts. 22 and 23).

Frequently asked questions

How often can the rent be adjusted?

Once a year: an adjustment clause with a period shorter than a year is void by operation of law (Law 10.192/2001, art. 2, § 1).

Which index should I use for the rent adjustment?

The one in the contract. The law does not choose the index: it only forbids tying the rent to the exchange rate or the minimum wage (Law 8.245/1991, art. 17).

What happens if the cumulative index is negative?

It depends on the contract. The calculator shows the calculation with the negative result, but the rent only goes down if the clause or an agreement between the parties allows it.

Can I ask for a review if the rent is above the market?

By agreement, yes (art. 18). Without agreement, the landlord or the tenant can ask for judicial review after three years of the contract or of the last agreement, to adjust the rent to the market price (art. 19).

Why does the result differ from the published cumulative index?

The calculator multiplies the monthly changes with two decimal places, as the Central Bank publishes them. The FGV and the IBGE calculate on the index numbers, and the difference is hundredths of a point.