What is the Inflation Calculator?
An Inflation Calculator models how an amount changes under an annual inflation assumption selected by the user. It can express a present amount in future rupees or translate a future amount into today's purchasing power.
The entered rate is a planning assumption, not a forecast for a household, category or future period. Actual price changes can differ materially.
How does it work?
The Inflation Calculator uses the standard compound interest formula applied to price growth: Future Value = Present Value × (1 + r)^n, where r is the annual inflation rate expressed as a decimal and n is the number of years. For example, if you want to know what ₹5,00,000 today will cost in 10 years assuming 6% annual inflation, the calculation is ₹5,00,000 × (1.06)^10 = ₹8,95,424. This tells you that you will need nearly ₹8.96 lakh in 10 years to afford what ₹5 lakh buys today.
The reverse calculation — finding the present value of a future cost — uses: Present Value = Future Value ÷ (1 + r)^n. This is useful when you know a future target (such as ₹20 lakh for a child's college fees) and want to understand its worth in today's money, or how much you must invest now at a given return to meet that goal. The real rate of return on any investment is calculated using the Fisher equation: Real Rate = ((1 + Nominal Rate) ÷ (1 + Inflation Rate)) − 1. This is the rate that actually grows your wealth after stripping out inflation.
The key inputs are the amount, a user-selected annual inflation assumption and the time horizon. Compare multiple rates to understand sensitivity instead of treating one result as a prediction.
Worked example
For ₹5,00,000 over 10 years at a user-entered 6% inflation assumption, the modeled future amount is ₹5,00,000 × (1.06)^10 = approximately ₹8,95,424. The result is conditional on that constant assumption.
When to use this calculator
- 1Retirement planning: Calculate how much your desired monthly lifestyle expense of, say, ₹50,000 today will cost in 25 years, and work backwards to determine your required retirement corpus.
- 2Compare future-cost scenarios for a goal using rates you select.
- 3Translate a nominal amount into an inflation-adjusted planning value.
- 4Test how sensitive a long-term plan is to different inflation assumptions.
Common mistakes to avoid
- ✕Treating one entered rate as a forecast for every expense category and future year.
- ✕Comparing a nominal investment result with an inflation-adjusted goal without using consistent units.
- ✕Assuming the calculator selects an appropriate inflation rate for your circumstances.
- ✕Leaving taxes, fees or changing consumption patterns out of an interpretation when they are not modeled.
Frequently asked questions
- What inflation rate should I use?
- Enter a planning assumption appropriate to the scenario you want to test and compare more than one rate. NiyamFin does not prescribe a category-specific inflation forecast.
- Can I compare inflation with a savings or investment rate?
- You can compare user-entered scenarios, but product rates, taxes and inflation can all change. Verify current product terms separately.
- What is the difference between CPI and WPI inflation in India, and which one should I use?
- CPI (Consumer Price Index) measures the price change of a basket of goods and services purchased by households and is the most relevant measure for personal financial planning. WPI (Wholesale Price Index) tracks price changes at the wholesale/producer level and is more relevant for businesses. RBI uses CPI as its primary inflation target. For all personal finance calculations — retirement, education, or lifestyle planning — always use CPI or sector-specific consumer inflation.
- Does the result predict my actual future cost?
- No. It is a constant-rate illustration based on the amount, rate and horizon entered.
- Does this model currency changes for an overseas goal?
- No. Currency movement and destination-country costs require separate assumptions that this calculator does not collect.