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Free Inflation Calculator for New Zealanders

Inflation erodes the purchasing power of money. The RBNZ targets CPI inflation in a 1-3% band, with a 2% midpoint. Even modest rates compound noticeably over a decade or two.

Your money

$1,000
$
$100$100k
3.00%
%
0%15%
10 years
yrs
150
Future cost
$1,344
to buy what costs $1,000 today

$1,000 today at 3.00% inflation over 10 years.

Future cost (nominal)$1,344
Equivalent value today (real)$744
Real loss in purchasing power$256
Cumulative inflation34.4%

About our Inflation Calculator

$100 today buys about $66 worth of goods in 30 years at the RBNZ’s 2% midpoint, or $41 at 3%. The calculator shows both the future nominal price and the real-purchasing-power loss for any inflation assumption.

How to use it

Enter the present-day price, the inflation rate, and the years out. The calculator returns the future nominal price and the equivalent purchasing power.

Why use it

For long-run planning around savings, retirement, and budgeting. Nominal projections overstate the real-purchasing-power figure; the calculator helps translate between the two.

The maths behind it

Formula: Future value = Present value × (1 + inflation rate)years

Inflation compounds. A 2% annual rate over 30 years raises prices by 81%. A 3% rate over 30 years raises prices by 143%. The Reserve Bank’s CPI target band is 1-3%; the midpoint of 2% is the typical long-run NZ planning figure.

Worked example

A $50 weekly grocery shop in 1995 vs 2025 NZ.

$50 in 1995 buys about $99 worth of 2025 groceries (NZ CPI roughly doubled over the 30 years).

If NZ inflation continues at the RBNZ’s 2% midpoint over the next 30 years, today’s $200 weekly shop will cost about $362 in 2055.

The real cost (purchasing power) is unchanged; the nominal figure on the receipt rises with inflation. Wages typically rise alongside, but at a different pace.

Things to keep in mind

  • CPI is an average. Stats NZ’s Consumers Price Index averages across categories. Specific items (housing, electricity, vegetables, petrol) inflate faster or slower than the headline CPI in any given year.
  • Wages do not always keep up. NZ wage inflation has run roughly with CPI over decades, but lagged in some periods. Real wage growth (wage rise minus inflation) varies year to year.
  • The 2% midpoint is a target, not a guarantee. The RBNZ targets 1-3% CPI on average. Actual NZ inflation has run above and below the band in shorter periods (peaking near 7% in 2022).

NZ-specific notes

Stats NZ
Consumers Price Index. Stats NZ publishes quarterly CPI data tracking NZ price-level changes by item category.
Source
RBNZ
CPI target band. The Reserve Bank operates monetary policy to keep CPI inflation between 1% and 3% on average over the medium term, with a 2% midpoint focus.
Source
RBNZ
Historical inflation. NZ inflation has averaged 2-3% since the inflation-targeting regime started in 1990. Earlier decades saw double-digit inflation in the 1970s and 1980s.
Source

FAQs

Is 2% inflation a lot?

Year on year, no. Compounded over 20-30 years it adds up: prices roughly 50% higher after 20 years at 2%, doubled after about 35 years.

Is high inflation bad for everyone?

Holders of cash and fixed-interest investments lose purchasing power; holders of inflation-linked assets (property, equities, inflation-linked bonds) usually keep pace better. Borrowers benefit from inflation eroding real debt; lenders lose.

How does this affect retirement planning?

Retirement projections in nominal dollars overstate real-purchasing-power balances. Subtract your inflation assumption from the assumed return rate when planning long-term retirement; a 6% nominal return at 2.5% inflation is a 3.4% real return.

References & sources

  1. Stats NZ, "Inflation". stats.govt.nz
  2. Reserve Bank of New Zealand, "Monetary policy mandate". rbnz.govt.nz
  3. Reserve Bank of New Zealand, "Historical interest and price data". rbnz.govt.nz

Last reviewed

Reviewed 6 May 2026, current to the RBNZ 1-3% CPI target band

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Disclaimer: This calculator is for information only and is not financial advice. Real inflation paths vary year to year and by category; the calculator’s constant-rate assumption is a long-run planning tool, not a forecast. Calculator.org.nz is not a registered Financial Advice Provider.