Instant
No Calculate button
Every input updates the chart, tiles, and year-by-year table in real time. Change the rate, see the slope move.
Compound Interest Calculator
Live updates · inflation-adjusted · year-by-year schedule. Runs entirely in your browser.
Live·Updates on every change
Future value
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After
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Contributed
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Principal + deposits
Interest earned
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Effective APY
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Growth over time
Principal, contributions, and interest — stacked year by year.
PrincipalContributionsInterest
Year-by-year breakdown
Opening balance, deposits, interest, closing balance.
Show table
Year-by-year breakdown
Opening balance, deposits, interest, closing balance.
| Year | Opening | Net flows | Interest | Closing |
|---|
What's different
A calculator that doesn't waste your time.
Most compound interest calculators are padded with ads, hidden behind a "Calculate" button, or missing the inputs that matter. This one isn't.
Honest
Inflation-adjusted real value
A million in 40 years is not a million today. We show you the real-dollars number next to the nominal.
Flexible
Deposits that match reality
Monthly, quarterly, or yearly contributions — at the start or end of each period. Mix with any compound frequency.
Shareable
The URL is the scenario
Every input is in the link. Send a scenario to a friend; they land on exactly what you saw.
Portable
CSV export, printable view
Download the full year-by-year schedule, or print a clean one-page summary for your records.
Private
Your inputs never leave the browser
The whole calculator runs in your browser. No tracking cookies, no sign-up, no form submission.
How it works
The math behind the slope.
Compound interest follows a single formula. We run a month-by-month simulation so your deposit timing, compound schedule, and contribution frequency are honored exactly — not approximated.
Formula
A = P (1 + r/n)nt + PMT · [ ((1 + r/n)nt − 1) / (r/n) ]
- A — future value
- P — initial amount
- PMT — contribution per period
- r — annual rate (decimal)
- n — periods per year
- t — years
Pick your frequency
Dedicated pages for each schedule.
Daily
Daily compound interest
How savings and high-yield accounts actually post interest — 365 times a year.
Monthly
Monthly compound interest
The default for mortgages, loans, and most retirement scenarios.
Quarterly
Quarterly compound interest
Common for CDs, bonds, and some dividend-reinvestment plans.
Continuous
Continuous compound interest
The theoretical ceiling — A = Pert. Daily is the practical stand-in.
401(k)
401(k) compound interest
Payroll contributions plus the employer match, modeled over decades.
Roth IRA
Roth IRA compound interest
Tax-free growth with inflation-adjusted today's-dollars output.
With withdrawals
Compound interest with withdrawals
Drawdown planning — enter a negative monthly amount to drain the balance on a schedule.
About the tool
The compound interest calculator that respects your time.
Every input in this compound interest calculatorupdates the chart, the summary tiles, and the year-by-year table the instant you type. No "Calculate" button, no page reload, no sign-up — just the number you want, when you want it. If you have ever compared the investor.gov compound interest calculator, the NerdWallet compound interest calculator, the Bankrate compound interest calculator, or the Ramsey compound interest calculator, you already know what each one is missing. This tool bundles the useful bits — live math, inflation adjustment, deposit timing, tax drag, and a shareable URL — into one page that loads instantly and runs entirely in your browser. The result is a compound interest calculator that behaves like a spreadsheet without being one.
Pick any compounding schedule
Match the schedule to your account. Use thedaily compound interest calculatormode (often searched as "compound interest calculator daily") for high-yield savings, money market accounts, and most online bank CDs — n = 365, interest posted every day. Switch to themonthly compound interest calculator— the phrasing "compound interest calculator monthly" shows up a lot because it is the default for mortgages, auto loans, and the vast majority of retirement scenarios. Thequarterlyoption matches a traditional CD compound interest calculator. The annual compound interest calculator mode handles bond-style instruments and textbook problems. And the continuous compound interest calculator mode applies A = Pert for the mathematically ideal limit. One tool, five frequencies, zero spreadsheet.
Built for real money, not textbook examples
Compound interest is the headline, but real plans have deposits, withdrawals, inflation, and taxes. Use this compound interest calculator with withdrawals to drain the account on a schedule and still see the end balance — useful for drawdown and early-retirement planning. The 401k compound interest calculator preset layers employer-matched monthly deposits onto a long horizon so you can project a realistic retirement balance (the "compound interest calculator 401k" workflow most people are Googling). The Roth IRA compound interest calculator preset turns off the tax drag — because qualified withdrawals are tax-free — and keeps inflation adjustment on so the future-value number is honest. Start-of-period and end-of-period deposits are both supported. Need a simple compound interest calculator view to compare linear versus compounded growth? Toggle the schedule and the chart recalculates in real time, so the gap between simple interest and the compounding tail is impossible to miss.
Honest numbers: APY, inflation, and taxes
Most online calculators quote a nominal rate and call it a day. This one shows the effective APY next to it, so a 5% nominal rate with daily compounding correctly reads as 5.127% APY — and the same 5% compounded monthly reads as 5.116%. Flip on the inflation adjustment and the summary tile splits in two: the raw future value and the "today's dollars" number. A million dollars in 40 years at 3% inflation is worth roughly $306,000 of today's purchasing power — the kind of fact a planning tool should refuse to hide. Add a tax rate and the calculator deducts the drag on annual interest, which matters for a taxable brokerage but should stay at zero for a Roth IRA or HSA.
Multi-currency and private by default
If you landed here from the Dave Ramsey compound interest calculator or searched for a compound interest calculator SBI–style tool to project a rupee-denominated savings account, you are in the right place. Currency support covers USD, EUR, GBP, INR, JPY, and more. No server call ever runs. No account, no email, no cookie banner, no tracking pixel — every scenario lives in your browser and in the share-link you choose to copy. If you want the number, we give you the number — and we show the math underneath so you can audit it. Open the calculator, change one input, and watch the slope move.
FAQ
Frequently asked
What is compound interest?
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Compound interest is the interest you earn on both your original money and the interest it has already earned. The longer the money sits, the more each year of interest adds to the base — which is why it accelerates with time.
How does this calculator decide when interest is added?
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You pick a compound frequency — annually, semi-annually, quarterly, monthly, or daily — and the calculator applies the matching rate, so your effective yield is exactly (1 + r/n)^n − 1. More-frequent compounding gives a slightly higher effective yield, shown as APY in the summary next to how long your money takes to double.
Can I include monthly deposits?
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Yes. Under Regular contributions, choose Deposits and enter an amount and a frequency — monthly, quarterly, or annually. You can also raise the deposit each year by a percentage or a fixed amount to keep pace with pay rises. Choose Withdrawals or Both to model drawing money out.
What does the inflation setting do?
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It shows your future balance in today's money alongside the raw future value. A $1,000,000 nest egg in 40 years at 3% inflation is worth about $306,000 in today's purchasing power.
Is the calculator accurate?
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It runs a month-by-month simulation, so any mix of compound frequency, deposit and withdrawal schedules, yearly increases, and partial-year horizons is calculated exactly rather than approximated. With no contributions, the result matches the standard formula A = P(1 + r/n)^(nt).
Does it store my inputs?
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No. The calculator runs entirely in your browser and never sends your inputs to a server. To save or share a scenario, use Copy link — it creates a URL with your inputs built in.
Start compounding, keep compounding.
Open the calculator, change one number, and watch the long tail.