Inflation-Adjusted Savings Calculator NZ

This calculator shows what your savings are actually worth once inflation is taken into account, rather than just the dollar figure your bank statement shows. It matters because a balance can climb every year and still buy less over time if the interest you earn does not keep pace with rising prices. You enter your current savings balance, the interest rate you earn after tax, the inflation rate you expect, and the number of years you plan to leave the money growing. The calculator then works out the future balance in dollar terms, converts that figure back into today's money to show its real value, and reports the real change in buying power alongside the real return per year, which is roughly your interest rate minus inflation. A real return above zero means your savings are getting ahead; a negative one means they are quietly losing ground even as the number on your statement grows. Use an after-tax interest rate for the most accurate picture, since tax further reduces what you actually earn. This is useful for comparing term deposits, savings accounts and other cash holdings against inflation to see whether they genuinely grow your wealth or simply tread water. The figures are an estimate based on the rates you enter, not a forecast or financial advice, since real inflation and interest rates change from year to year.

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Savings balance

Interest rate (after tax)

Inflation

Years

$52,493

value in today's dollars after inflation

Future balance (dollars)$67,196

Real change$2,493

Real return per year0.49%

Use an after-tax interest rate for the truest picture. A real value below your starting balance means your savings are losing buying power despite a growing dollar balance. Estimate only, not financial advice.

How it works

The calculator grows your balance at the interest rate for the years, then discounts that future balance back by inflation to express it in today's dollars. The real change is the difference between that and your starting balance, and the real return per year is roughly the interest rate minus inflation. It reveals whether your savings are genuinely growing or just keeping up with, or falling behind, rising prices.

Worked example

$50,000 earning 3% after tax for 10 years grows to about $67,200 in dollars, but with 2.5% inflation that is only about $52,500 in today's money, a real gain of just $2,500. A lower rate would leave you going backwards in real terms.

Related calculators

Real Return Calculator: return after tax and inflation.
Inflation Calculator: effect of inflation.
Savings Calculator: regular saving.
Term Deposit Calculator: term deposit returns.
Inflation Adjusted Thinking: background on this topic.

Frequently asked questions

What does inflation do to savings?

Inflation erodes the buying power of money over time. If your savings earn less than the inflation rate, they grow in dollars but shrink in what they can actually buy. This calculator shows the future balance in today's dollars so you can see the real change.

How do I keep ahead of inflation?

Your savings need to earn at least the inflation rate after tax just to hold their value. Beating it usually means accepting some investment risk; cash and low-rate accounts often lose value in real terms once tax and inflation are counted.

What is a real return?

The real return is your interest rate minus inflation, roughly. If you earn 4% and inflation is 3%, your real return is about 1%. A negative real return means your money is losing buying power even as the balance grows.