Calcs4All

APR 23 · 2026

Savings calculator

Estimate future savings from a starting balance, monthly deposits, APY, and years.

What this calculator covers

Use this savings calculator to estimate how a starting balance and monthly deposits can build over time at a stated APY.

Because APY is an annual yield, the calculator first converts it into an equivalent monthly rate before applying monthly savings math.

The result breaks the final balance into contributed dollars and interest earned so you can see what portion of the growth came from saving versus compounding.

Frequently asked questions

Why does the calculator use APY instead of a simple annual interest rate?
APY already accounts for how often interest compounds within the year, so it gives a more accurate picture of actual growth than a stated annual rate that compounds at a different frequency. Converting APY into a monthly rate lets each month's deposit grow consistently with that stated yield.
Does the starting balance earn interest the same way as monthly deposits?
Yes, but the starting balance has more time to compound. It grows through every month in the horizon, while each new deposit only begins compounding from the month it is added.
What is not included in this projection?
The estimate ignores taxes on interest, account maintenance fees, and any rate changes over time. Real returns after taxes and fees will typically be lower than the projected balance.
How much does deposit timing matter?
This calculator assumes deposits happen at the end of each month. Moving deposits to the start of each month would give each one an extra month of compounding, which modestly increases the ending balance — particularly over longer horizons.

Tool

Run the calculation

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yr

RESULT · SAVINGS BALANCE

â„–074

Primary result

$52,907.55

$5,000.00 with $300.00 saved each month at 4.50% APY grows to $52,907.55 over 10 years.

Ending balance
$52,907.55
Total contributed
$41,000.00
Total interest
$11,907.55
Equivalent monthly rate
0.3675%

Step-by-step solution

  1. 1.Translate the APY into an equivalent monthly rate: 4.50% APY becomes 0.3675% per month.
  2. 2.Count the monthly saving horizon: 10 years = 120 monthly deposits.
  3. 3.Compound the starting balance and the end-of-month deposits to reach $52,907.55, with $11,907.55 coming from earned interest.

Walkthrough

Visual walkthrough

A savings projection starts with the APY, converts it into monthly growth, and then layers in each monthly deposit one month at a time.

  1. 01

    Convert APY into monthly growth

    (1 + APY)^(1 / 12) - 1 = 0.3675%

    APY is an annual yield, so monthly savings math needs the equivalent monthly rate before compounding begins.

  2. 02

    Project the full monthly deposit schedule

    120 monthly deposits

    Each end-of-month deposit has fewer months to grow than the money already in the account.

  3. 03

    Separate cash in from interest earned

    The final balance can be split into contributed dollars and the interest generated by those dollars over time.

    $11,907.55 interest earned