Savings Interest Calculator
See the interest before and after tax, and the total you will have at maturity.
| Total deposited | |
| Interest before tax | |
| Tax on interest | |
| Interest after tax |
How it works
For a lump-sum deposit, simple interest is amount x rate x (months / 12). For a monthly plan, each deposit is made at the start of the month and earns interest only for the months it stays in the account. With monthly compounding, one-twelfth of the annual rate is added to the balance every month.
Here is the catch with monthly plans: put 1,000 a month into a 4% plan for a year and you will not earn 4% of 12,000. The interest is about 260 before tax, an effective return of roughly 2.2%. If you already have the lump sum, a deposit at the same rate always earns more.
For long-term growth with regular contributions, try the compound interest calculator. Borrowing instead? Use the loan repayment calculator.
Frequently asked questions
Why does a monthly savings plan earn less than the advertised rate?
With a lump-sum deposit, all of your money earns interest for the full term. With a monthly plan, each deposit only earns interest for the months left until maturity. The first deposit earns 12 months of interest, the last one earns just one, so the effective return is roughly half the headline rate.
What is the difference between simple and monthly compounding?
Simple interest is paid only on the money you put in. With monthly compounding, the interest is added to your balance every month and starts earning interest itself. Over one year the difference is small, but it grows with longer terms and higher rates.
What should I enter for tax on interest?
It depends on where you live and the account type. Many tax-free or tax-advantaged accounts pay interest with no tax deducted, so the default is 0%. If your bank withholds tax on interest, enter that rate to see what you actually receive.
Is the result exactly what my bank will pay?
It should be very close, but banks differ in how they count days, when they credit interest and how they round. Use the result as a planning estimate and check the account terms for the exact figure.
Estimates only. Banks differ in day counts, crediting dates and rounding, so small differences are normal.