Savings growth calculator
Find out what regular saving can add up to. Enter what you have now, what you add each month, the yearly interest rate and the time, and see the balance build year by year.
How the savings growth calculator works
Compound interest means you earn interest on your interest. Each month the calculator adds the monthly rate to your balance, then adds your deposit. Early on, most of the growth is your own money going in. Later, the interest itself starts doing the heavy lifting.
The table splits the balance into what you paid in and what the interest has earned, so you can see the crossover point for yourself.
The formula behind it
Each month: new balance = old balance × (1 + r) + deposit, where r is the annual rate ÷ 12.
A worked example
Start with $1,000, add $100 a month at 5% for 10 years. You pay in $13,000 in total. The balance ends at $17,175.24, of which $4,175.24 is interest.
Questions people ask
Is this guaranteed?
No. It is a projection at a steady rate. Real savings and investment returns go up and down, and the rate on a savings account can change.
What is the rule of 72?
A quick estimate: divide 72 by the annual rate to guess how many years it takes to double. At 6%, about 12 years.
Does inflation matter?
Yes. If prices rise 3% a year, a 5% return is only about 2% in real terms. Think about what the money will actually buy.
Should I start early or save more?
Starting early is powerful because of the extra years of compounding. Saving more helps too. Doing both is best.