Compound Interest Calculator with Inflation

* DENOTES A REQUIRED FIELD
Step 1: Initial Investment

Amount of money that you have available to invest initially.

$
Step 2: Contribute

Amount that you plan to add to the principal every month, or a negative number for the amount that you plan to withdraw every month.

$

Annual rate at which the monthly deposit or withdrawal grows. Applied to both positive contributions and negative withdrawals so they keep pace with inflation.

Length of time, in years, that you plan to save.

Step 3: Interest Rate

Your estimated annual interest rate.

Range of interest rates (above and below the rate set above) that you desire to see results for.

Step 4: Compound It

Times per year that interest will be compounded.

What is a Compound Interest Calculator with Inflation?

Most compound interest calculators assume that the amount you deposit (or withdraw) each month never changes. In real life, that's rarely true — a $500 contribution today doesn't carry the same weight as a $500 contribution twenty years from now. This calculator lets you set an annual inflation rate that automatically grows your monthly contribution year over year, so the model reflects what your savings rate will likely look like as wages and costs rise.

How the Inflation Adjustment Works

Each year, the monthly amount is multiplied by (1 + inflation rate). If you start at $500/month with 3% inflation, year two becomes $515, year three is roughly $530.45, and so on. The same rule applies to negative numbers — useful if you're modelling a retirement drawdown that grows with inflation.

Monthlyyear n = Monthlyyear 1 × (1 + Inflation %)n − 1

When to Use This Calculator

Real Return vs Nominal Return

The headline final balance shown here is a nominal figure — it doesn't discount the result back to today's dollars. To estimate real return, set your interest rate to the gap between your expected nominal return and your inflation rate. For example, a 7% return with 3% inflation gives a real return of roughly 4%.

Frequently Asked Questions

Does the inflation rate also affect the interest rate?

No — inflation here only scales the monthly contribution. The interest rate field is independent so you can model nominal returns. If you want to model real returns, use the rate gap (nominal − inflation) as your interest rate input.

What's a realistic inflation rate to use?

For the US, long-run averages sit between 2–3%. India has historically averaged 4–6%. Eurozone targets sit near 2%. Use what feels right for your geography; this tool lets you stress-test different scenarios with the interest-rate variance field.