Last updated: 2026 assumptions reviewed. Assumptions & sources
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Compound Interest Calculator

If I invest $500 a month for 25 years, what do I end up with? See the real numbers, watch the growth chart, and see why starting early is one of the most important financial decisions you can make.

The three parts of any balance
What you put in→What it earns→What the earnings earn
The third box is the whole point. It is small for years, and then it is larger than everything you ever contributed. If you want the plain version of the mechanism first, read how money actually grows.

Your Investment Plan

A one-tap starting point. Adjust anything below.
$
What you're investing today. Can be $0.
$500
$
7.0%
Historical average for a balanced Canadian portfolio: 5 to 8 percent. Use 7 percent as a sober starting point for long-term equity funds.
25 years
years old
Used to show your age at each milestone in the table below. Leave it blank if you would rather not see ages.
Your deposits still go in monthly. This setting only changes how often the return is credited, so monthly gives the highest result at the same posted rate. Index funds are closest to monthly.
Restates the projection in the purchasing power you recognize today by taking inflation out of the return.
% inflation

Your Results

$0
Final Value
$0
Total Contributed
$0
Growth
0%
Growth vs What You Put In
The shaded band is growth. Watch it overtake what you actually contributed.

Growth here is modelled tax-free, the way it grows inside a TFSA, and each deposit is counted at the start of its month. Fees are not modelled. To see what a fund fee costs you, subtract its MER from the return rate: a 2% mutual fund turns 7% into 5%. Every figure the site's calculators use is listed in the assumptions.

Money that grows on its own raises a fair question for a Christian. What the Bible says about compound interest works through it.

Year-by-Year Growth

Projected balance at each milestone year, with what you contributed and the growth on top of it.
Year Age Total ContributedPut in Balance Growth

Swipe the table sideways to see every column.

Return Rate Benchmarks

High-interest savings (HISA)
Around 2.8 to 3.5% on everyday accounts in September 2026, a little above the Bank of Canada policy rate of 2.25%. Safe, liquid. Good for emergency funds and short-term saving.
Conservative balanced fund
~4 to 6% long-term. Mix of bonds and equities.
Broad market index fund
~7 to 10% long-term before inflation. The S&P 500 has averaged ~10%. Canadian market somewhat lower.
After inflation (real return)
Subtract about 2% from nominal returns. A 7% nominal return is roughly 5% real over time, which is what the toggle for today's dollars shows.

The Rule of 72

Divide 72 by your annual return rate to see how long your money takes to double. At 7%: 72 ÷ 7 = ~10 years. At 10%: ~7.2 years.

Where to invest

In Canada: start with TFSA for flexibility, then RRSP if high income (the deduction is worth real money). FHSA if you're a first-time buyer. It's the best deal in Canadian tax law right now.

Never opened an investment account? The walkthrough for starting to invest in Canada with a small amount covers the first deposit.

Not sure which? Use the RRSP vs TFSA tool →
Tools Dan uses

Start the compounding

These numbers only matter once real money is invested. Wealthsimple lets you start with $1, no minimum, and automate a monthly contribution so compounding actually begins.

Open a Wealthsimple account →

Affiliate link, no cost to you. How this works. See the full list of tools Dan recommends.

Frequently Asked Questions

What is compound interest?

Compound interest is interest earned on both your principal and the interest already accumulated. Unlike simple interest (which only earns on the original amount), compound interest grows exponentially over time. A dollar invested at 7% doubles in about ten years.

How often does compound interest compound?

It depends on the account. A high-interest savings account usually credits interest monthly. A GIC often credits it once a year. An index fund credits no interest at all, because its value moves with the market every day. At the same posted rate, crediting more often leaves you with slightly more, which is why this calculator models monthly growth unless you change the setting.

What return should I assume for long-term investing in Canada?

For diversified index fund portfolios, historical long-term returns have averaged around 7 to 10% before inflation. Take 2% off for inflation and a real return of 5 to 8% is a reasonable planning figure. More conservative projections use 5 to 6% before inflation.

How does starting early affect compound interest?

Dramatically, and you can run it yourself above. $200 a month from age 25 to 65 at 7% reaches $528,025 on $96,000 of contributions. A man who waits until 35 and puts in $300 a month for the next 30 years contributes $108,000 and reaches $368,126. He puts in $12,000 more and finishes about $160,000 behind. The first ten years of growth cannot be bought back later.

Is compound interest the same as the Parable of the Talents?

The parable is about faithfulness with what you were given, and the principle rhymes. The servant who invested and grew what he was given was commended. The servant who buried it out of fear was rebuked. Compound interest is one mechanism by which faithful stewardship of resources over time produces growth. It is a tool worth understanding, and no one can promise you the rate.