Compound interest calculator
See how savings grow with monthly deposits. The calculation does not deduct tax, as in a TFSA or RRSP.
| Year | Paid in | Balance |
|---|---|---|
| 1 | $10,600 | $10,964 |
| 2 | $14,200 | $15,090 |
| 3 | $17,800 | $19,384 |
| 4 | $21,400 | $23,852 |
| 5 | $25,000 | $28,503 |
| 6 | $28,600 | $33,343 |
| 7 | $32,200 | $38,381 |
| 8 | $35,800 | $43,623 |
| 9 | $39,400 | $49,079 |
| 10 | $43,000 | $54,758 |
How it works
Each month your deposit is added and one month of interest (the yearly rate divided by 12) is paid on the whole balance. Over long periods the interest earned on past interest becomes the largest part of the total.
Examples after 10 years
| Start | Monthly | Rate | After 10 years |
|---|---|---|---|
| $1,000 | $100 | 3% | $15,358 |
| $7,000 | $300 | 4% | $54,758 |
| $10,000 | $0 | 5% | $16,470 |
| $0 | $583 | 4% | $86,133 |
Tax on interest in Canada
Interest in a regular savings account is fully taxable at your marginal rate every year, even if you leave it in the account. Inside a TFSA it is never taxed: the 2026 contribution limit is $7,000, and unused room carries forward. Inside an RRSP it grows tax-deferred and is taxed when you withdraw. On $60,000 of salary in Ontario the marginal tax rate is 28.1%, so a 4% rate outside a TFSA keeps only about 2.9% after tax.
Debt compounds too
A credit card at 20% interest grows faster than any savings account pays. Paying off expensive debt first is usually the best guaranteed return available. Mortgage prepayments save interest at your mortgage rate, tax-free, but the money is harder to get back.
Common questions
What is $10,000 at 5% for 10 years?
About $16,470 with monthly compounding and no further deposits.
How much will a full TFSA contribution grow?
$7,000 at 4% a year becomes about $15,558 after 20 years, all tax-free if it stays in the TFSA.
Does the calculator include tax?
No. It shows growth before tax. Interest outside a TFSA or RRSP is taxed every year as income, which lowers your real return.
How often is interest compounded?
This calculator compounds monthly. Many high-interest savings accounts pay monthly, while GICs often pay once a year or at maturity.
Sources
Checked September 28, 2026. OneCalcs is independent and not affiliated with the Canada Revenue Agency, Revenu Québec or any provincial government.