How inflation changes what money is worth
Inflation raises prices over time, which means the same amount of money buys progressively less. Any long-horizon financial plan that ignores it will overstate what the final amount can actually purchase.
The calculation runs in two directions. Forward, it tells you what something costing a given amount today will cost in future. Backward, it tells you what a future sum is worth in today's purchasing power — usually the more sobering of the two.
Worked example
Monthly household expenses of 50,000 today, projected forward 20 years at 6% annual inflation.
| Input | Value |
|---|
| Current monthly expense | 50,000 |
| Assumed inflation | 6% per year |
| Period | 20 years |
| Equivalent expense in 20 years | 1,60,357 |
| Value of 1,00,000 after 20 years | 31,180 |
At 6%, prices roughly triple every 20 years. This is why a retirement corpus sized against today's expenses falls badly short, and why an investment returning 7% against 6% inflation is barely growing in real terms.
How to use this calculator
- Enter an amount — a current expense, or a future sum you want valued in today's terms.
- Set an assumed annual inflation rate.
- Set the number of years.
- For planning, apply the future figure to your goal amount, not the present one.
- Compare your expected investment return against the inflation rate to see real growth.
Frequently asked questions
What inflation rate should I assume?
Long-run averages differ by country and by category. Note that personal inflation often exceeds the headline rate, because education and healthcare — large items for most households — typically rise faster than the general index.
What is the difference between nominal and real return?
Nominal return is the headline growth figure. Real return subtracts inflation and reflects the change in actual purchasing power. An investment returning 8% while inflation runs at 6% has a real return near 2%.
Why does inflation matter so much for retirement?
Because the horizon is long and the corpus must last decades after you stop earning. A plan built on today's expenses can be short by a factor of three or more by the time it is needed.
Does inflation affect loans too?
It works in a borrower's favour for fixed-rate debt. The instalment stays constant in nominal terms while incomes and prices rise, so the real burden of the repayment falls over time.
How is the inflation rate measured?
Typically by tracking the price of a representative basket of goods and services and reporting the percentage change. Because the basket is an average, it may not match your own spending pattern closely.
This calculator is an educational tool. Results are estimates based on the inputs you provide and do not constitute financial advice. Verify figures with your bank, broker or a qualified advisor before acting on them.