How is inflation calculated?

Inflation uses the standard compound-growth formula FV = P × (1 + r)^t, where P is today's cost or amount, r is the annual inflation rate as a decimal, and t is the number of years. To find today's purchasing power of a future amount, the same formula is inverted: PV = F / (1 + r)^t. This calculator applies the formula at the rate and horizon you provide and shows a year-by-year curve.

What is the average inflation rate to use?

Headline CPI inflation has long-term averaged around 5-6% per year, and the Reserve Bank of India targets 4% ± 2% — so most general-purpose long-horizon planning uses 6%. Category-specific inflation is very different: education and healthcare typically inflate at 8-12%, well above CPI, so college fees and hospital bills should be modeled at a higher rate. Use the headline 6% only when the cost you're modeling tracks the overall consumer basket.

What's the difference between nominal and real returns?

Nominal return is the headline percentage your investment earned (e.g. 12% from an equity mutual fund). Real return is what you earned after subtracting inflation — the actual increase in your purchasing power. The Fisher approximation is real ≈ nominal − inflation, so a 12% nominal return at 6% inflation gives roughly a 6% real return (more precisely, (1.12 / 1.06) − 1 = 5.66%). Long-horizon planning should always use real returns; nominal returns alone overstate how much you can actually buy.

Why does education inflation matter more than CPI?

Engineering, medical, and management programme fees have historically risen 8-12% per year — well above the headline CPI of 5-6%. A ₹10 lakh undergraduate degree today, modeled at 10% inflation over 15 years, becomes roughly ₹41.8 lakh. Using the headline 6% rate would understate that target by nearly half. If you're saving for a child's college, always model at category-specific education inflation, not CPI.

How do I plan for inflation in retirement?

First, project today's monthly lifestyle forward using a 6-7% inflation rate over your years to retirement — that's the income you will need in the first year of retirement. Second, since you'll be drawing income for 25-30 years after that, you also need the corpus to keep up with inflation through retirement (use a Systematic Withdrawal Plan or annuity that adjusts upward). Third, your investments should target a real return of at least 3-4% above inflation — that's a nominal 9-10% in a 6% inflation environment, achievable with equity-heavy portfolios over long horizons.

Inflation Calculator — Future Cost & Purchasing Power

Inflation

💰 Finance

Inflation Calculator

Calculate the future cost of today's money under a given inflation rate, and the real purchasing power of a future amount in today's terms. Useful for retirement planning, education-goal sizing, and any long-horizon financial decision.

Reviewed by the CalculatorKosh Editorial TeamUpdated June 2026Free · No sign-up

Inflation Details

Direction

Amount today

₹

₹1₹100 Cr

Inflation rate (annual)

0%20%

Years

yrs

1 yr50 yrs

Drag sliders to explore different scenarios

Inflation Rate6%

0%15%

Years10 yrs

1 yrs50 yrs

What-If Future Cost

₹1,79,085

Future cost

₹1,79,085

(₹1,00,000 today will cost ₹1,79,085 in 10 years)

Cost increase

₹79,085

Change %

79.08%

Effective annual decay

6.00%

Inflation context

India's CPI inflation typically runs 4-7% per year (RBI target: 4% ± 2%). Healthcare and education costs often inflate at 8-12% — well above headline CPI. If you're planning for a child's college 15 years out, model at 10% — not the CPI 6%.

Future cost over time

Drag sliders to explore different scenarios

Inflation Rate6%

0%15%

Years10 yrs

1 yrs50 yrs

What-If Future Cost

₹1,79,085

How It Works

Inflation is the rate at which the general price level rises year after year — and equivalently, the rate at which a rupee in your hand today loses purchasing power. Modelling inflation matters for any goal that sits more than a few years out: retirement income, a child's college fees, a future home down-payment, or a real-return view of any investment.

Inflation formulas

Forward (today → future cost): FV = P × (1 + r)^t

Reverse (future amount → today's value): PV = F / (1 + r)^t

Where P = present amount, F = future amount, r = annual inflation rate as a decimal (6% → 0.06), and t = years.

Headline CPI vs category-specific inflation

The Reserve Bank of India targets headline CPI at 4% ± 2%, and the long-run average has been around 5-6%. But the CPI basket is a blend — and within it, education and healthcare have historically inflated much faster (often 8-12% per year). For category-specific goals, model the right rate: 6% for general lifestyle, 10% for college fees, 8-10% for healthcare. Using the headline 6% for everything under-budgets education and healthcare goals by a wide margin over 15-20 year horizons.

Nominal vs real returns

A 12% nominal return on an equity mutual fund at 6% inflation is approximately a 5.66% real return — that's the actual rate at which your purchasing power grows. The exact formula (Fisher equation) is real = (1 + nominal) / (1 + inflation) − 1. Long-horizon planning should always frame target corpus in real terms, then convert to nominal at the assumed inflation rate at withdrawal time.

Frequently Asked Questions

This calculator uses the standard compound-growth formula FV = P × (1 + r)^t, where P is today's cost or amount, r is the annual inflation rate as a decimal, and t is the number of years. For example, ₹1,00,000 today at 6% inflation over 10 years becomes ₹1,00,000 × (1.06)^10 = ₹1,79,085. To find today's purchasing power of a future amount, the formula is inverted: PV = F / (1 + r)^t — so ₹1,00,000 in 10 years at 6% inflation has the purchasing power of just ₹55,839 today.