Compound Interest Calculator

Future value and growth in one panel.

InputsMonthly$100.00 monthlyLive

Core plan

Starting balance

Years

Annual rate

Rate type

Compounding

Contributions

Deposit amount

Deposit frequency

Deposit timing

Adjust for inflation

Projected balance

$31,998.32

Growth $9,998.32

Effective APY

5.1162%

Inflation 2.5%

Deposits

$22,000.00

120 scheduled deposits

Growth

$9,998.32

Compounding return

Entered rate

Nominal annual rate

Inflation-adjusted

$24,997.04

Real annual return 2.5524%

Growth milestones

Year 1$11,739.50

Deposits +$1,200.00Growth +$539.50

Year 3$15,490.06

Deposits +$1,200.00Growth +$722.05

Year 6$21,866.60

Deposits +$1,200.00Growth +$1,032.41

Year 8$26,679.91

Deposits +$1,200.00Growth +$1,266.68

Year 10$31,998.32

Deposits +$1,200.00Growth +$1,525.54

Milestone	Ending balance	Deposits added	Interest added
Year 1	$11,739.50	$1,200.00	$539.50
Year 2	$13,568.01	$1,200.00	$628.50
Year 3	$15,490.06	$1,200.00	$722.05
Year 4	$17,510.44	$1,200.00	$820.39
Year 5	$19,634.20	$1,200.00	$923.75
Year 6	$21,866.60	$1,200.00	$1,032.41
Year 7	$24,213.23	$1,200.00	$1,146.62
Year 8	$26,679.91	$1,200.00	$1,266.68
Year 9	$29,272.79	$1,200.00	$1,392.88
Year 10	$31,998.32	$1,200.00	$1,525.54

Compounding comparison

Annual

$31,725.26

Growth $9,725.26

Quarterly

$31,947.25

Growth $9,947.25

Monthly

Selected

$31,998.32

Growth $9,998.32

Daily

$32,023.26

Growth $10,023.26

Assumptions and formula

Future value is computed with periodic compounding and optional recurring deposits at period start or end. Inflation adjustment, when enabled, reports purchasing-power value using the entered annual inflation rate.

Formula

FV = P(1 + r/n)^(nt) + sum of C(1 + r/n)^(n(t - deposit time))

Use nominal annual rate r as a decimal, or convert the entered APY to an equivalent nominal rate.
Use n as compounding periods per year and keep deposit frequency independent.
Grow each deposit C from its own deposit time to the end of the term.

Example

Worked example: 10000 at 5% compounded monthly for 10 years

1 A = 10000(1 + 0.05/12)^(120)
2 A = 16470.09
3 Interest = 6470.09

Future value is about 16470.09.

How

Enter your starting balance, term, annual rate, and whether the rate is nominal or APY.
Choose compounding separately from your deposit amount, frequency, and timing.
Review future value, interest growth, inflation-adjusted value, real annual return, milestones, and a fair frequency comparison.
Copy or download a summary report and export the milestone schedule as CSV when you need to share assumptions.

Avoid

Using percent as whole number in formula without decimal conversion.
Confusing a nominal annual rate with APY.
Treating monthly deposits as daily deposits when comparing compounding frequencies.
Ignoring fees, taxes, market volatility, or inflation in a long-term projection.

Ref only. Verify assumptions, fees, taxes.

FAQ

What is compounding frequency?

It is how many times interest is applied per year.

Can I use yearly compounding?

Yes, set compounds per year to 1.

Does this include extra contributions?

Yes. Set an amount, deposit frequency, and beginning- or end-of-period timing independently from compounding.

Can I export the results?

Yes. You can copy or download a summary report and export the milestone schedule as CSV.

What is the difference between APY and a nominal rate?

APY already includes the effect of compounding. A nominal annual rate does not, so its effective annual yield changes with compounding frequency.

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Compound Interest Calculator