What the inflation calculator does
The tool converts a lira amount from one month into the amount with the same purchasing power in another month. For example, 100,000 TL in January 2015 equals 1,743,386 TL at September 2026 prices. It also works backwards, showing what today’s amount was worth then.
Type an amount, pick a start and an end month, and choose a direction. You get the equivalent amount, cumulative inflation, the geometric annual average, the purchasing-power loss and a table of year-end values. Copy the result card as text, download it as a PNG or share it with a link.
Months run from January 2005 to the latest published month; the end month defaults to the latest one.
How it is calculated
Every month TÜİK publishes the percentage change of the CPI against the previous month, and the tool stores only those monthly rates. Each rate becomes a factor of 1 + rate/100, the months in between are multiplied together, and every month end gets an approximate price level (S).
equivalent amount = amount × S(end month) ÷ S(start month)A level represents the end of its month, so January 2015 to September 2026 multiplies the 140 monthly changes from February 2015 to September 2026. The factor is 17.4339: 100,000 TL × 17.4339 = 1,743,386 TL. Cumulative inflation is 1,643.39%, the geometric annual average 27.76% and the purchasing-power loss 94.26%. The annual average is the factor to the power of 12/months, minus one.
| Period | Factor |
|---|---|
| January 2015 → September 2026 | 17.4339 |
| January 2020 → September 2026 | 9.7803 |
| January 2005 → September 2026 | 38.1462 |
| September 2025 → September 2026 | 1.2972 |
In reverse, the amount belongs to the end month and is divided by the factor, the exact inverse of the forward calculation. Equal months give a factor of 1.
Data source and updates
The source is TÜİK’s (TurkStat) consumer price index. A machine-readable copy of its monthly and annual changes sits in the CBRT consumer prices table, which the tool uses. The series starts in January 2005. The data line on the page always shows the latest month and when the data was taken.
The data is refreshed after each new TÜİK bulletin. The release day is not fixed: the September 2026 figures came out on 5 October 2026 at 10:00 (monthly 1.84%, annual 29.73%). An update never silently changes the values of past months.
From January 2026 the CPI is published with 2025=100 as the base year and the ECOICOP v2 classification. That changes the year the index counts as 100 and how products are classified, while the historical percentage changes were preserved (TÜİK notice). So the tool never mixes index levels with different bases: it stores only percentage changes and builds an approximate chain from them.
Before 2005 and the six zeros
On 1 January 2005 six zeros were removed from the Turkish lira: 1 New Turkish Lira equalled 1,000,000 old liras. Because the series starts in January 2005, every amount is in current lira, and the tool does not support dates before 2005. Divide an amount in old lira by 1,000,000 first; months before 2005 still give no result.
Annual inflation versus the 12-month average
Two different rates appear in the news. Annual inflation is the change of the latest month against the same month a year earlier: 29.73% for September 2026. The 12-month average inflation compares the average index of the last 12 months with the average of the 12 months before: 31.49% for the same month (TÜİK bulletin, 5 October 2026).
Which rate applies matters in some calculations, such as rent increases. A rent increase calculator that uses the published 12-month average is being prepared separately. This tool uses month-end levels to show long-term purchasing power.
Limits and cautions
- The CPI measures an average basket. The weight of rent, food, education or health differs between households, so your personal inflation can differ.
- The result summarises past prices; it does not forecast future inflation or the value of an asset.
- The chained calculation is approximate: rounded monthly rates give 29.72% instead of the official 29.73% for September 2026 annual inflation.
- To estimate what a foreign payment is worth in lira after fees, use the receiving money from abroad calculator; this tool only works with CPI purchasing power.
This tool is for information only; it is not investment, tax or legal advice.
Frequently asked questions
Why can another calculator give a slightly different result?
The result depends on the method. This tool uses month-end levels and monthly rates rounded to two decimals. Another tool with a different month rule or rounding can differ slightly.
Annual inflation is 29.73%, so why is the factor from September 2025 to September 2026 1.2972?
A factor of 1.2972 corresponds to 29.72%. The official value is 29.73%; the difference of a hundredth of a percentage point comes from rounding the monthly rates to two decimals.
Which months can I choose?
From January 2005 to the latest month with data. Future months are not forecast, and dates before 2005 give no result.
How do I share the result card?
Copy the card as text or download it as a PNG. The copy link button gives the page address; if Include inputs in the link is ticked, the amount, months and direction go into the link, and anyone with it can read them. Nothing is sent to a server.
When is the data updated and where is the source?
Every month, after TÜİK publishes its bulletin. The source table is on the CBRT consumer prices page. Check the Latest data line on the page.