Inflation adjustment with IPCA, IGP-M and INPC
What is an amount from months or years ago worth today? The calculation uses the official monthly change of each index.
- IPCA
- R$1,045.76
- Initial amount
- R$1,000.00
Use the legend buttons to show or hide a series.
R$1,045.76
R$1,000.00 in September 2025 equals R$1,045.76 in September 2026, based on the IPCA change of 4.58% over 12 months.
- Cumulative change
- 4.58%
- Adjustment factor
- 1.045761
- Months applied
- 12
The start month is not included: its change was already in that month's price. The following months, up to and including the end month, are applied. If your contract sets another index, base date or frequency, the contract prevails.
Source: IBGE, IPCA index, via the Central Bank of Brazil (SGS, series 433). Latest release: September 2026.
How the calculation works
How inflation adjustment with IPCA, IGP-M and INPC works
Choose the index, amount and start and end months. This tool treats the amount as an end-of-month value: it compounds the following monthly changes through the end month. The chart tracks the adjusted amount; “Compare indices” adds the series available over the same interval.
A worked example
Starting with R$1,000.00 at the end of the initial month and hypothetical changes of 1% and 2% in the next two months, the calculation is 1,000 × 1.01 × 1.02 = R$1,030.20. These are illustrative rates, not observed inflation.
Common questions
Which index should I use for rent or a contract?
Use the index and adjustment frequency specified in your contract. Comparing IPCA, IGP-M and INPC helps explain differences, but does not change what the parties agreed.
Why is the start month excluded?
Here, the amount refers to the end of that month. The Central Bank’s Calculadora do Cidadão uses the start of the month and includes its rate. Align the date convention when comparing results.
What happens if an index month is missing?
The calculator explains the problem and does not return an adjusted amount for that interval. Missing data is never treated as zero inflation.
Sources and methodology
Methodology and maintenance: Today Brazil. Guide updated on .
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Informational simulation built on public data. It is not investment advice, nor financial, legal or tax advice.