Savings Calculator
Plan your savings growth.
Details
Total savings
$45,489
After 10 years at 4% APY
This projects what your savings will be worth. Enter a starting amount, what you add regularly, the interest rate and how long you are saving for.
It returns the final balance, split into what you put in and what the interest earned, so you can see which of the two is doing the work.
How savings grow
Savings grow from two things: the money you put in, and the interest that money earns. Over long periods interest takes over, but over the timeframes most people actually save for, your deposits do most of the work.
Interest compounds, meaning you earn interest on interest already earned. That is what makes the curve bend upwards rather than climb in a straight line, and it is why starting earlier beats saving harder later.
The rate to compare is the APY, not the headline interest rate. APY already includes the effect of compounding, so it is the only figure that lets you compare two accounts fairly.
Over ten years the deposits are about three quarters of the result. Interest only overtakes contributions over much longer stretches, which is the real argument for starting early.
What to enter
- Initial deposit
- What you are starting with. Zero is fine if you are starting from nothing.
- Contribution
- What you add regularly. This is usually the number with the most influence over the outcome.
- Interest rate (APY)
- Use the APY from the account, since it already accounts for compounding. Comparing a nominal rate against an APY makes one account look better than it is.
- Years to save
- How long the money stays invested. Time matters more than rate over long periods.
- Contribution increase
- An optional yearly rise in what you add, for matching pay increases. Small annual increases compound surprisingly hard.
What this assumes
The rate stays the same throughout. Real savings rates move, sometimes a great deal.
Interest is not taxed in this projection. In a normal savings account it usually is, which reduces the real return.
Inflation is ignored, so the final figure is in future dollars, not today's buying power.
How to calculate how much your savings will grow
Two things grow at once: the lump sum you started with, and each deposit you have made since.
- rate
- The annual rate divided by how many times a year interest is added
- deposit
- What you add each period
Convert the rate. Divide the annual rate by the number of periods. Monthly compounding at 5% is about 0.4167% a month.
Grow the balance. Multiply what you already have by 1 plus that rate.
Add the new deposit. Then repeat for the next month. Each deposit starts earning from the moment it lands, which is why paying in earlier in the month helps slightly.
See a worked example: $1,000 to start, $200 a month, 5% APY, 10 years
- Starting amount
- $1,000
- Monthly deposit
- $200
- Rate
- 5% APY
- Time
- 10 years
Total paid in: $1,000 + ($200 × 120 months) = $25,000.
Final balance after compounding: $32,703.47.
So the interest earned is $7,703.47.
Raising the deposit to $300 a month would add about $16,000, far more than any realistic rate increase would.
$32,703.47, of which $7,703.47 is interest
Frequently asked questions
The interest rate is the plain annual rate. APY is what you actually earn once compounding is included, so it is always the higher of the two.
Always compare accounts on APY. A 5% rate compounded monthly works out to about 5.12% APY, and comparing one bank's rate against another's APY is not a fair comparison.
Over realistic timeframes, saving more wins by a wide margin. In the example above, adding $100 a month more is worth about $16,000 over ten years. Moving from 5% to 6% is worth roughly $2,000.
That said, moving cash from a near-zero account to a competitive one is free money and takes an afternoon. Do that once, then focus on the contribution.
Adjust the years until the final balance reaches your target. Because growth is not linear, the last stretch always arrives faster than the first.
As a rough check, the Rule of 72 says money doubles in about 72 ÷ rate years. At 6%, that is roughly 12 years.
In an ordinary savings account, generally yes. In the US, interest is taxable as income and the bank reports it once it passes a threshold.
Tax-advantaged accounts change this considerably, which is why retirement saving often belongs in a 401(k) or IRA rather than a savings account.
It can. If your account pays 3% and inflation runs at 4%, your balance grows while its buying power shrinks.
This projection is in future dollars. To see what a sum is worth in today's terms, run it through the inflation calculator.
Problems people actually run into
Chasing rate instead of raising the deposit
People spend weekends comparing accounts for an extra quarter point and never revisit the amount they pay in each month. Over ten years the deposit is by far the bigger lever.
Switch once to a competitive account, set the transfer to leave on payday, then increase it whenever your pay rises. That routine beats rate-shopping comfortably.
Assuming today's rate lasts the whole term
Savings rates move with the wider economy, and an introductory bonus rate often expires after a year and quietly reverts to something much lower.
A ten-year projection at today's headline rate is optimistic. Check the rate you are actually being paid once a year rather than assuming it held.
Results are estimates for general information only and are not professional financial, medical, or legal advice. Read our full disclaimer.
Last updated: September 3, 2026