Money calculators · Updated
Savings Calculator
Estimate how a starting balance and recurring deposits may grow. Enter APY or an interest rate, and see your own deposits separately from projected interest.
Annual yield used: 4.074%. Recurring deposits: 120. Taxes, fees and inflation are excluded.
| At year | New deposits | Interest in period | Balance |
|---|---|---|---|
| Start | $5,000.00 | $0.00 | $5,000.00 |
| 1 | $3,600.00 | $270.45 | $8,870.45 |
| 2 | $3,600.00 | $428.13 | $12,898.58 |
| 3 | $3,600.00 | $592.25 | $17,090.83 |
| 4 | $3,600.00 | $763.05 | $21,453.87 |
| 5 | $3,600.00 | $940.80 | $25,994.68 |
| 6 | $3,600.00 | $1,125.80 | $30,720.48 |
| 7 | $3,600.00 | $1,318.34 | $35,638.82 |
| 8 | $3,600.00 | $1,518.72 | $40,757.54 |
| 9 | $3,600.00 | $1,727.26 | $46,084.80 |
| 10 | $3,600.00 | $1,944.30 | $51,629.10 |
How deposit frequency changes the projection
A $100 weekly deposit adds $5,200 over a model year. A $400 monthly deposit adds $4,800. The deposit amounts must be compared on the same time basis; choosing a different frequency can change both total deposits and how long the money earns interest.
The following examples start at $0, use a constant 4% APY for five years and place deposits at the end of each period. They are projections, not available account offers.
| Plan | Total deposits | Projected interest | Final balance |
|---|---|---|---|
| $100 each week | $26,000.00 | $2,713.66 | $28,713.66 |
| $200 every two weeks | $26,000.00 | $2,702.83 | $28,702.83 |
| $400 each month | $24,000.00 | $2,471.61 | $26,471.61 |
APY, compounding and the savings formula
Annual growth factor G = (1 + interest rate ÷ n)^n If entering APY: G = 1 + APY Initial balance at T = starting balance × G^T Each deposit at time t = deposit × G^(T − t) Projected balance = initial growth + growth of all scheduled deposits
Rates in the formula are decimals, and time is measured in years. The calculator places deposits at intervals of 1 divided by the selected deposits per year. It uses the equivalent annual growth factor between those dates, including fractional compounding periods.
For a partial final year, end-of-period deposits count only when due by the horizon. Beginning-of-period deposits count at each period start before the horizon. A zero-year projection contains the starting balance only. Actual bank results can differ because of calendar dates, rate changes, tiered balances, fees and interest-crediting rules.
Frequently asked questions
Should I enter APY or the interest rate?
Choose the matching rate type. APY already includes the effect of compounding, so the calculator uses it directly. If you enter a nominal interest rate, choose its compounding frequency so the calculator can derive an annual yield. Do not apply another compounding uplift to an APY.
How much will I have if I save $300 a month?
Starting at $0, with deposits at the end of each month and a constant 4% nominal rate compounded monthly, the projection is $44,174.94 after ten years or $110,032.39 after twenty. The twenty-year total includes $72,000.00 of deposits and $38,032.39 of interest. These are illustrative rates, before taxes, fees and inflation.
How does compound interest work on savings?
Interest can earn additional interest after it is compounded. At a 4% nominal rate compounded monthly, $10,000 with no new deposits earns $407.42 in the first year. A 4% APY instead produces exactly $400 in this fixed-yield, one-year example.
Are weekly deposits averaged into monthly deposits?
No. The model places weekly deposits at 52 equally spaced times per year, biweekly deposits at 26, and twice-monthly deposits at 24. It applies equivalent growth for each deposit’s remaining time. Actual calendar dates, leap years and a bank’s daily-balance and posting rules are not modeled.
What does beginning versus end of period mean?
Beginning-of-period deposits start immediately and repeat before the projection ends. End-of-period deposits begin after one full deposit period and are included when due by the end. For a whole number of periods, depositing earlier gives the same deposits more time to grow. A partial final period can also change how many deposits occur.
Is savings interest taxable, and is the balance insured?
Bank interest is generally taxable when it is credited and available to you. Taxable interest must be reported even if no Form 1099-INT arrives; the form is generally issued for $10 or more. FDIC coverage is generally $250,000 per depositor, per insured bank, per ownership category, subject to its rules. This projection does not determine your tax or insurance coverage.
Does the calculator account for inflation?
No. Results are nominal dollars. For a lump sum, an inflation-adjusted annual growth rate can be calculated as (1 + annual yield) ÷ (1 + inflation rate) − 1. Recurring deposits and changes in prices over time require additional assumptions; this tool does not forecast inflation.
Related calculators
Sources and updates
Methods and figures reviewed on . Provider rates and terms can change; check the linked source and your own account terms.
- CFPB, Annual Percentage Yield Calculation: interest and compounding
- Investor.gov (SEC), compound interest calculator
- FDIC, Understanding Deposit Insurance
- IRS Topic 403, Interest received
This calculator gives estimates for information only and is not tax, legal or financial advice. Actual outcomes depend on the assumptions, timing, taxes, fees and terms that apply to you. See how we calculate.