Inflation: Why ₹100 Shrinks
Why the same snack costs more every year, how India measures it, and how to make sure your savings keep up.
From 0.25% to 5.54% in eleven months
In October 2025, India’s retail inflation fell to 0.25%, the lowest since the current consumer price series began. Vegetable prices had collapsed after a good harvest, GST cuts had just lowered the price of packaged goods, and the previous October had been unusually expensive, which made the comparison look even softer. Economists began asking whether India might face falling prices.
Eleven months later, in September 2026, retail inflation was 5.54%. A war in the Gulf had pushed oil above $100 a barrel, the rupee had hit record lows, and the weakest monsoon since 2009 had cut harvests. Onions cost more than twice what they had a year earlier. The RBI, which had cut interest rates through 2025, raised them in October 2026. The same households, the same shops, the same country, and in under a year the price story had turned upside down. Understanding why is the subject of this unit.
What will ₹1,000 buy in the future?
Prices will be about 3.2× higher. By the rule of 72, they double roughly every 12 years.
Set an inflation rate and a number of years to see how much buying power a fixed amount of money loses.
What Inflation Measures
Inflation is the rate at which the general level of prices rises over time, usually measured over twelve months. When inflation is 5%, a basket of things that cost ₹1,000 a year ago now costs about ₹1,050. It is a rate of change, not a level: 0.25% inflation does not mean prices are low, only that they barely rose over the year.
India measures retail inflation with the Consumer Price Index, published every month by the Ministry of Statistics. The index tracks the prices of hundreds of items, from rice, milk and vegetables to rent, school fees, bus fares, medicines and mobile plans, in towns and villages across the country. Each item carries a weight equal to its share in a typical household’s spending. Since January 2026 the index uses 2024 as its base year, with food weighted a little less and housing and services a little more than in the old series, to match how households spend today.
Why Prices Rise
Economists group the causes of inflation into two families. Demand-pull inflation happens when people and businesses try to buy more than the economy can produce: too much money chasing too few goods, as in the mango village of Unit 1. Cost-push inflation happens when the cost of producing things rises and businesses pass it on: an oil shock, a bad harvest, a weaker rupee that makes imports dearer, or higher wages.
Oil: India imports about 85% of its crude oil. When oil rises, transport, plastics, fertiliser and cooking gas all become more expensive, and those costs spread through the economy.
The monsoon: nearly half of India’s farmland depends on rain. A weak monsoon cuts the supply of vegetables, pulses and onions, and food prices jump.
The rupee: a weaker rupee makes everything priced in dollars, from crude oil to edible oil to electronics, cost more in rupees.
Demand: when incomes and credit grow quickly, spending can outrun supply, especially in services like restaurants and travel.
The 2026 rise was mostly cost-push. The Gulf war raised oil prices, the rupee fell to around ₹97 per dollar in May, and the monsoon failed. In September 2026, food inflation was 7.74%, and eating out rose 9.36%. Rural inflation, at 6.08%, ran well above urban inflation at 4.88%, because rural families spend a larger share of their budget on food.
Purchasing Power and Real Returns
Inflation’s most important effect on you is on purchasing power: how much a fixed amount of money can buy. ₹100 kept in a drawer stays ₹100, but every year of inflation means it buys a little less. Over long periods the effect is enormous.
At 6% inflation, ₹100 today has the buying power of about ₹31 in twenty years. That is why money for long-term goals cannot simply sit in a savings account. What matters is the real return, roughly the interest rate minus inflation. A 6.5% FD in October 2025, when inflation was 0.25%, delivered a real return above 6%. The same FD in September 2026, at 5.54% inflation, delivered under 1%.
Who Fights Inflation, and How
By law, the RBI must aim to keep CPI inflation at 4%, within a band of 2% to 6%. Its main tool is the repo rate. Raising it makes loans more expensive, so households borrow and spend a little less and businesses delay expansion, which eases price pressure. Lowering it does the opposite. Six members of the Monetary Policy Committee vote on the rate roughly every two months.
Monetary policy works best against demand-pull inflation. It cannot make it rain or bring oil prices down. So why did the RBI raise rates in October 2026 when much of the inflation came from oil and the monsoon? Because persistent price rises can change expectations. If workers and businesses start to believe prices will keep rising, they demand higher wages and set higher prices, and inflation feeds itself. A rate hike signals that the central bank will not let that happen.
Deep Dive: Headline, Core and Food
The headline inflation number includes everything. Because food and fuel prices jump around with weather and world markets, economists also watch core inflation, which leaves them out. Core inflation shows the underlying trend in prices that respond more slowly, such as rent, education, healthcare and clothing.
When headline inflation is high but core is calm, the problem is usually a temporary shock that may pass on its own. When core inflation rises too, prices are rising more broadly, and the RBI is more likely to act. In 2025, headline inflation fell to record lows while school fees, rent and doctors’ fees kept rising. In 2026 the pattern reversed. Reading both numbers together tells you far more than either alone.
Case Study: Why Onions Doubled
Onions are a small item in the CPI basket but a big item in Indian politics and kitchens. They are grown mainly in a few states, harvested in specific seasons and stored for months, with a large share lost to rot. Demand barely changes when prices rise, because almost every Indian dish uses them. Economists call that inelastic demand. Put these together and a small fall in supply produces a large jump in price.
In 2026, with the monsoon running about 15% below normal by mid-September, onion crops in Maharashtra and Karnataka suffered, and by September prices were up more than 100% on a year earlier. The government sold onions from its buffer stock at subsidised prices. This pattern, a weather shock in one region becoming a national price spike, has repeated in 2013, 2019 and 2023. It shows why food inflation in India is so hard to control with interest rates alone, and why better storage and supply chains matter as much as monetary policy.
Check yourself
0/12 answered1. Inflation of 0.25% means:
2. What does the Consumer Price Index track?
3. Since January 2026, India’s CPI uses which base year?
4. A war that pushes up oil prices mainly causes:
5. Why did rural inflation run higher than urban inflation in September 2026?
6. From Fig 5.2, at 6% inflation, ₹100 today buys about how much in 20 years?
7. An FD pays 6.5% when inflation is 5.54%. The real return is about:
8. The RBI’s legal inflation target is:
9. How does raising the repo rate reduce inflation?
10. Core inflation leaves out:
11. Why is deflation, a sustained fall in prices, usually bad?
12. Why do onion prices swing so sharply?
Pick five items your family buys regularly, such as a litre of milk, a kilo of onions, a bus or auto fare, a movie ticket and a school or tuition fee. Find their prices today and five years ago (ask a parent, or check old bills). Calculate the yearly rise for each and compare it with the official CPI. In 150 to 200 words, explain why your family’s inflation might differ from the national number.