How to build your inflation forecast
Follow these steps in order. The calculator converts your monthly assumptions into projected index values, annual inflation and average inflation.
Choose the dataset. Select Euro Area HICP, US CPI-U or Italy NIC and the required precision.
Choose the reference period. You may start from an earlier official month; known indices and monthly changes are loaded automatically and locked.
Enter a monthly change. Assumptions can be entered only for months after the latest official data.
Extend the forecast. Add one month or repeat the same assumption for a chosen number of months.
Read the results. Compare projected annual inflation, year-to-date average inflation and the chart.
Calculation: next index = current index × (1 + monthly change ÷ 100). Annual inflation compares each projected index with the same month one year earlier; different index bases are linked automatically when required.
Euro Area (HICP)
Index: 133,62
(August 2026)
Annual change (August 2026): 3,2%
Monthly change (August 2026): 0,4%
United States (CPI-U)
Index: 336,94
(September 2026)
Annual change (September 2026): 3,7%
Monthly change (September 2026): 0,6%
Italy (NIC with tobacco)
Index: 104,6
(September 2026)
Annual change (September 2026): 4,2%
Monthly change (September 2026): 0,7%
What will be the next inflation index for September 2026?
👉 Selected dataset: Euro Area – HICP
The index for the previous year stood at 129,530
Baseline scenario (0,4 percentage point, same variation as previous month): 134,15 3,6% y/y
Optimistic scenario (+0,3 percentage point): 134,02 3,5% y/y
Pessimistic scenario (+0,5 percentage point): 134,29 3,7% y/y
Stable scenario (no change) (0,0 percentage point): 133,62 3,2% y/y
Dataset and precision
Published months are official and read-only. Forecast assumptions begin with the month after the latest available observation.
| Month | Index | Monthly change (%) | Actions |
|---|
| Month | Index, same month last year | Projected index official / linked when required | Expected monthly change (%) | Projected annual inflation | Average annual inflation (ytd) |
|---|
Latest Values
| Monthly change: | 0,4% |
|---|---|
| Annual change: | 3,2% |
| Latest month available: | August 2026 |
| Previous month available: | July 2026 |
Index Levels
| Latest Euro Area Harmonised Index of Consumer Prices (HICP) index: | 133,62 |
|---|---|
| Euro Area Harmonised Index of Consumer Prices (HICP) index one year ago: | 129,42 |
| Reference: | NIC |
What it does
This tool provides an interactive way to forecast consumer price indices (Euro Area HICP, USA CPI-U, Italy NIC with tobacco) using baseline, optimistic and pessimistic scenarios derived from user-defined monthly variations.
- Select data source – choose the dataset to use: Euro Area (HICP, Eurostat), USA (CPI-U, BLS) or Italy (NIC with tobacco, ISTAT).
- Set reference period – choose the last available month and index value (default: latest data).
- Apply monthly variation – enter the expected monthly change in %.
- Add months – extend the projection one month at a time.
- Compare scenarios – baseline (same as last month), optimistic (–0.1%), pessimistic (+0.1%).
- Check results – see projected indices, monthly changes, and annual inflation in the summary table and chart.
The calculator applies a simple compounding formula:
Next index = Current index × (1 + Expected change / 100)
Annual inflation is measured against the same month of the previous year.
| Area | Source dataset | Notes / Release schedule | Methods and definitions | Geographical information |
|---|---|---|---|---|
| Euro Area |
|
Flash estimate issued at the end of each reference month. Full HICP data released mid-month. |
Annual inflation = price change vs. same month prev. year. Monthly inflation = price change vs. previous month. |
Belgium, Germany, Estonia, Ireland, Greece, Spain, France, Croatia, Italy, Cyprus, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Austria, Portugal, Slovenia, Slovakia, Finland. Data adjusted with chain index formula when composition changes. |
| United States |
|
Monthly CPI released usually within two weeks after reference month. Includes seasonally adjusted and unadjusted data. |
Annual inflation = % change CPI vs. same month prev. year. Monthly inflation = % change vs. previous month. |
Covers all urban consumers (approx. 93% of U.S. population). Data collected across U.S. metropolitan areas. |
| Italy (NIC_T) |
|
Provisional estimates end of month. Final NIC data released around middle of following month. |
Annual inflation = % change vs. same month prev. year. Monthly inflation = % change vs. previous month. NIC includes all consumption, tobacco included. |
National coverage – Italy. Harmonised with Eurostat rules for comparability. |