Savings Calculator
Project a savings balance from an opening deposit and a monthly contribution, with interest applied and compounded monthly.
Balance at the end
$22,331.69
After 5 years
Total deposited
$20,000.00
Interest earned
$2,331.69
- Opening balance
- $2,000.00
- Monthly deposits total
- $18,000.00
- Interest rate per month
- 0.333%
- Growth on interest
- 11.7%
- Balance after 1 year
- $5,748.22
How this was calculated
- 1.Monthly rate i = 4% ÷ 12 = 0.333%; periods n = 60.
- 2.Opening balance grows to $2,441.99.
- 3.Deposits grow to $19,889.69 (deposits are added at the end of each month).
- 4.Total = $2,441.99 + $19,889.69 = $22,331.69.
Assumes a constant rate credited monthly and no withdrawals, tax or fees.
How the savings calculation works
Regular saving combines two things: the growth of the opening balance, and the growth of each monthly deposit from the day it arrives. The second part is an annuity, which is why the formula has two terms.
Deposits are assumed to be made at the end of each month, the standard convention for savings calculations. Making them at the start would add roughly one extra month of interest on every deposit.
Worked example
$2,000 to start, $300 a month, 4% a year, for 5 years.
- →n = 60 months, i = 0.003333
- →Opening grows to 2,000 × 1.003333⁶⁰ = 2,442
- →Deposits grow to 300 × ((1.003333⁶⁰ − 1) ÷ 0.003333) = 19,899
Answer: About $22,341 — of which $20,000 is your own money.
Savings FAQs
Should I use gross or net interest?
Use the rate you actually receive after tax, unless the account is tax-free. Entering the gross rate will overstate the balance.
Can I model irregular deposits?
Not here — this assumes equal monthly deposits. For a lump sum plus one contribution pattern, the investment calculator lets you vary the return instead.
What if the rate changes?
Run the calculation again with the new rate. Variable-rate savings products change often, so treat any long projection as a range rather than a promise.
Savings Calculator is part of the financial calculators collection on Calcora, alongside 8 other tools. Results are calculated in your browser and are for information only — see our disclaimer.
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