How to use
- Choose a question: future cost, future value of money, or adjust using two CPI values.
- Enter the amount, then the inflation rate and years, or the starting and ending CPI.
- Press Calculate to see the adjusted amount and the cumulative change.
Formula / how it works
What inflation measures. Inflation is the rate at which the general level of prices rises, so the same money buys less. It is usually measured by a consumer price index (CPI): the cost of a fixed basket of goods and services, such as food, rent, fuel, transport and healthcare, tracked over time. The US Bureau of Labor Statistics publishes CPI-U, the UK Office for National Statistics publishes CPI and CPIH, and the Pakistan Bureau of Statistics publishes national CPI with separate urban and rural figures.
Future cost. At a constant annual rate, a price grows as amount × (1 + rate)^years. Something costing PKR 100,000 today would cost about PKR 196,715 in ten years at 7% a year: prices almost double. Inflation compounds just like interest, so 7% for ten years is a 96.7% cumulative rise, not 70%.
What money will be worth. The second question runs the other way: amount ÷ (1 + rate)^years gives the purchasing power, in today's money, of a sum you will have in the future. 100,000 received in ten years at 7% inflation buys what about 50,835 buys now. This is why savings earning less than inflation lose value in real terms, even as the balance rises.
Using two CPI values. For exact historical comparisons, use official index values: adjusted amount = amount × (CPI end ÷ CPI start). With the US CPI-U annual average of 258.811 for 2020 and 313.689 for 2024, 100 dollars in 2020 equals about 121.20 in 2024, a 21.2% rise. The index base does not matter, as long as both numbers come from the same series. Look up the figures from the official statistics office; this calculator does not store CPI data, so it works for any country or currency.
Rule of 70. Divide 70 by the inflation rate to estimate how many years it takes for prices to double: about 23 years at 3%, 10 at 7% and under 6 at 12%.
Why your own inflation feels different. The CPI basket is an average. If you spend more than average on rent, food or fuel, and those rose faster, your personal inflation is higher. Official figures also adjust for quality changes and substitution, which some people find unintuitive. For planning, it is reasonable to use a rate a little above the official target, or a category-specific rate, for example education or medical costs, which have often outpaced general inflation.
Typical rates.
- Central bank targets: around 2% for the US Federal Reserve, the European Central Bank and the Bank of England.
- Pakistan has had much higher and more volatile inflation: CPI inflation averaged around 29% in fiscal year 2023 before falling sharply in 2024–25.
- Long-run averages matter more than one year's figure; a constant rate here is a simplifying assumption.
Uses.
- Retirement and education planning: how much a goal will cost when you reach it.
- Salary comparisons: whether a raise kept up with prices.
- Contract escalation clauses, rent reviews and historical comparisons, such as what a 1990 price means today.
This is an estimate for planning; official figures and actual prices will differ.
Worked examples
A cost ten years from now at 7%
Inputs: Question: What will it cost in the future?; Amount: 100000; Annual inflation %: 7; Years: 10; Currency: PKR
Choose the future cost question and enter PKR 100,000, 7% and 10 years. Compounding turns 7% a year into a 96.72% rise, nearly doubling the price.
Result: Something costing PKR 100,000.00 today would cost about PKR 196,715.14 in 10 years at 7% a year
Cumulative price rise: 96.72%
Adjusting 2020 dollars with CPI
Inputs: Question: Adjust using two CPI values; Amount: 100; Starting CPI: 258.811; Ending CPI: 313.689; Currency: USD
Choose "Adjust using two CPI values" and enter 100 with the CPI-U annual averages for 2020 and 2024. The ratio of the two index values gives 121.20, a 21.2% price rise.
Result: USD 100.00 at CPI 258.811 equals USD 121.20 at CPI 313.689
Total price change: 21.2%
Use cases
- Planning for future costs.
- Checking if a raise beat inflation.
- Comparing historical prices.
- Rent and contract reviews.
Tips & limitations
- Use official CPI for past comparisons.
- Pick a slightly higher rate for planning.
- Remember inflation compounds.
- Compare savings rates with inflation.
FAQ
How do I adjust a price for inflation?
Multiply by the ratio of the ending CPI to the starting CPI.
Where do I find CPI figures?
From your national statistics office, such as BLS, ONS or PBS.
Why does 7% for 10 years nearly double prices?
Because inflation compounds each year.
Does it include CPI data?
No. Enter the values or a rate yourself.
Can I use it for any currency?
Yes.
Is my data saved?
No. It runs in your browser.
Estimates for planning only, not financial or tax advice. Real lenders, payroll systems and tax offices apply rules and rounding this calculator may not; confirm figures with them or a qualified adviser.