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Inflation Calculator

See how inflation erodes purchasing power over time.

Reviewed by The QuickCalc Editorial Team · Last updated · About our methodology

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Result

Equivalent future amount
R170 814,45

Inputs & results at a glance

Updates live as you change the form above.

ItemTypeValue
Amount todayInputR100 000,00
Inflation rateInput5.5%
YearsInput10 years
Future equivalentResultR170 814,45

About this calculator

Inflation is the general rise in prices over time, which means the same amount of money buys less in the future. This calculator projects the future value of an amount adjusted for a constant annual inflation rate, so you can see the erosion of purchasing power over years or decades.

The formula is the same as compound growth in reverse: Future price = Present price × (1 + inflation)^years. So at 5% inflation, R100 today has the same buying power as R163 will in 10 years — put differently, R100 in 10 years will only buy what R61 buys today.

In South Africa, headline CPI has averaged roughly 5.5% per year over the last decade, though it has ranged from under 3% during 2020 to over 7% in 2022. The South African Reserve Bank targets a 3–6% inflation band. When planning for retirement, mortgage horizons or long-term investing, always sanity-check whether the growth rate you're assuming beats inflation by a meaningful margin.

How to use it

  1. 1Enter the amount. The Rand amount today (or at the starting date).
  2. 2Enter the inflation rate. Annual rate as a percentage, e.g. 5.5%.
  3. 3Enter the number of years. How far into the future you want to project.
  4. 4Read the future value. The nominal Rand needed to preserve today's purchasing power.

How it works

The calculator applies a constant annual inflation rate to a present amount to show its equivalent value at a future date. It's mathematically identical to compound interest — inflation compounds year on year.

Inflation matters because nominal returns are misleading. A 7% investment return during 6% inflation only grows real purchasing power by about 1%. Long-term financial plans should always compare returns to expected inflation to see if they preserve or grow real wealth.

Formula

Future value = Present × (1 + inflation)^years

Present = today's amount; inflation = annual rate as decimal; years = number of years forward.

Worked examples

R100 today at 5.5% for 10 years

You'd need about R171 in 10 years to buy what R100 buys today.

R1m today at 6% for 20 years

≈ R3.2m needed in 20 years for the same purchasing power.

Frequently asked questions

What is South Africa's average inflation rate?

CPI has averaged roughly 5.5% p.a. over the last decade, though it has ranged from under 3% to over 7% in individual years.

Why does R100 today buy less in 10 years?

Because average prices rise. At 5% inflation, R100 today buys the same as roughly R163 will buy in 10 years — so R100 in 10 years buys only 61% as much.

How is CPI measured?

Stats SA tracks a basket of consumer goods and services and reports CPI monthly. The Reserve Bank targets 3–6% inflation.

Should I use headline or core CPI?

Headline CPI is the standard reference. Core CPI excludes food and energy and is more useful for long-term planning.

What if inflation changes?

The calculator uses one constant rate. For long horizons, running the calculation at 4%, 5% and 6% gives a realistic range.

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