Inflation Calculator — see the real value of money over time

Inflation is the rate at which the general price level of goods and services rises over time. Statistical agencies measure it by tracking the cost of a fixed “basket” — the same loaf of bread, the same litre of petrol, the same rent across a representative sample of retailers — and publishing the cost as an index number called the Consumer Price Index (CPI). The CPI is set to a chosen reference year (e.g. 1982–84 = 100 for the US BLS series), so the index level is unit-free; only the ratio of two CPI values matters.

To express an amount of money from year A in year B prices, the calculator uses the standard inflation-conversion formula:

equivalent_B = amount × (CPI_B ÷ CPI_A)
total_inflation = (CPI_B ÷ CPI_A) − 1
annualised_rate = (CPI_B ÷ CPI_A)^(1 / years) − 1

The annualised rate is the constant per-year inflation that, compounded over the period, produces the same total. It is a geometric mean of year-on-year inflation rates, not an arithmetic average. For periods where some years had high inflation and others low — for example Sri Lanka 2019–2024, which spans the 2022 crisis — the geometric mean is the only honest summary. The calculator computes both the closed-form ratio and an independent year-by-year CPI chain, then verifies the two match.

The CPI tables are loaded statically from each country's authoritative agency: BLS for the United States, ONS for the United Kingdom, MoSPI for India, and the Central Bank of Sri Lanka / Dept. of Census & Statistics for Sri Lanka. Where an agency has rebased its index over time (Sri Lanka has done so in 2002, 2006/07, 2013, and 2021), the historical values are spliced into a single continuous series so that ratios across the splice points remain valid.

One caveat: CPI is a national average across a representative basket. Personal inflation can differ significantly — housing, education, and fuel often inflate faster than the headline figure, while electronics and clothing inflate slower. For investment or salary comparisons CPI is the standard reference; for “what does my specific spending actually cost now”, treat the headline number as an approximation.

Reference point: between 1950 and 2024 the US CPI-U rose from 24.1 to 313.689 — a factor of about 13.02×. One 1950 dollar buys roughly what 13 dollars buy today.

• U.S. Bureau of Labor Statistics — CPI-U, All Urban Consumers, All Items
• Office for National Statistics — CPI (D7G7) — Consumer Prices Index, All Items
• Ministry of Statistics and Programme Implementation — CPI (Combined, General Index)
• Central Bank of Sri Lanka / Dept. of Census & Statistics — Colombo Consumer Price Index (CCPI)

The CPI tables were last cross-checked against the official sources on 2026-05-11. Each table uses the agency's headline annual average. The page is reviewed when an agency publishes a new annual figure or revises prior years.