Compound Interest Calculator
Project compound growth in any currency — APY, optional deposits, rate of return, time to double, chart & yearly schedule. Free MyCalcsWorld compound tool.
Results · USD
Future value
- Interest earned
- $5,048.31
- Effective annual rate (APY)
- 7.23%
- Rate of return
- 100.97%
- Time to double
- 9.93 years
From nominal rate and compounding frequency
Gain ÷ total invested
Exact via EAR · Rule of 72 ≈ 10.3 y (principal only)
Growth chart· 10 years
Swipe chart horizontally if needed →
Yearly growth schedule· 10 years — scroll to review
- Year
- 1
- Interest
- $361.45
- Balance
- $5,361.45
- Year
- 2
- Interest
- $387.58
- Balance
- $5,749.03
- Year
- 3
- Interest
- $415.60
- Balance
- $6,164.63
Showing 3 of 10 rows — swipe the schedule below for the full table.
| Year | Interest | Balance |
|---|---|---|
| 1 | $361.45 | $5,361.45 |
| 2 | $387.58 | $5,749.03 |
| 3 | $415.60 | $6,164.63 |
| 4 | $445.64 | $6,610.27 |
| 5 | $477.86 | $7,088.13 |
| 6 | $512.40 | $7,600.53 |
| 7 | $549.44 | $8,149.97 |
| 8 | $589.16 | $8,739.13 |
| 9 | $631.75 | $9,370.88 |
| 10 | $677.42 | $10,048.31 |
Educational estimates · not financial advice · free, no signup
How this was calculated
A = P(1 + r/n)^(n·t) for a single principal. With regular deposits, each compounding period earns interest, then end-of-period deposits are added. Effective annual rate (APY) = (1 + r/n)^n − 1. Time to double uses ln(2)/ln(1+EAR). Rate of return = (ending − total invested) / total invested.
Want more detail? Full formula notes & FAQs ↓
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
Compound interest is interest on interest — the reason long-horizon savings can accelerate. MyCalcsWorld’s Compound Interest Calculator sets principal, nominal annual rate, years, and compounding frequency (annually through daily), then shows future value, interest earned, effective annual rate (APY), rate of return, and time to double — plus a growth chart and a full yearly schedule. Default demo scale is $5,000 at 7% for 10 years with monthly compounding (catalog defaults). Open Advanced options to add optional monthly or yearly deposits. Format money with the currency picker. Use SIP when you want a contribution-first mutual-fund view; use Loan / EMI or Mortgage when you are amortizing debt instead. Educational estimate only — not investment advice. Product day-count conventions and fees can differ.
When to use / who it helps
- Comparing savings or CD-style growth at a fixed rate and compounding schedule.
- Modeling regular monthly or yearly contributions alongside a starting principal.
- Reading APY / effective annual rate next to a nominal brochure rate.
- Checking time to double (exact EAR method vs Rule of 72).
- Reviewing a year-by-year deposits / interest / balance schedule before opening a spreadsheet.
How to use
Steps
- Enter Principal — demo default is 5000.
- Set Annual rate (%) — demo default is 7 (nominal).
- Set Years — demo default is 10.
- Choose Compounded frequency (monthly is common for savings; daily for some products).
- Optional: open Advanced options → set Regular deposits to Monthly or Yearly and enter Deposit amount.
- Read Future value, Interest earned, APY, Rate of return, Time to double, then scroll the yearly schedule.
How to interpret results
- Future value is ending balance after compounding and any deposits you entered.
- Interest earned = ending − principal − deposits (when deposits are on).
- Effective annual rate (APY) converts the nominal rate and compounding frequency into a once-per-year equivalent.
- Rate of return is simple gain ÷ total invested for this scenario — not a time-weighted market performance claim.
- Time to double is principal-only at this rate (exact via EAR); Rule of 72 is shown as a quick cross-check.
- Educational estimate — product day-count and fees can differ.
Common mistakes & gotchas
- Entering APY when the form expects a nominal annual rate (or the reverse).
- Leaving Regular deposits on None when you meant to model contributions — open Advanced options.
- Mixing years and months in the tenure field.
- Assuming the currency picker converts FX — use the Currency Converter for that.
- Treating rate of return as a guaranteed market return — it is gain ÷ total invested under your inputs only.
Worked example
Worked example — $5,000 at 7% for 10 years, monthly compounding
- P = $5,000; r = 0.07; n = 12; t = 10.
- A = 5,000 × (1 + 0.07/12)^(12×10) ≈ $10,048.
- Interest earned ≈ $5,048; APY = (1 + 0.07/12)^12 − 1 ≈ 7.23%.
- Time to double at this EAR ≈ ln(2)/ln(1.0723) ≈ 9.9 years (Rule of 72 ≈ 10.3 years).
- Enter 5000 / 7 / 10 / Monthly to mirror the live panel; currency picker only changes display.
- Optional: Advanced options → Monthly deposits to see a much higher ending balance.
Result: About $10,048 future value; roughly $5,048 interest over 10 years at 7% monthly — before taxes, fees, and any optional deposits.
Want these demo numbers in the form? Tap Try example above the Calculate button.
How to calculate / formula
A = P(1 + r/n)^(n·t) for a single principal. With regular deposits, each compounding period earns interest, then end-of-period deposits are added. Effective annual rate (APY) = (1 + r/n)^n − 1. Time to double uses ln(2)/ln(1+EAR). Rate of return = (ending − total invested) / total invested.
Frequently asked questions
What is compound interest?
Interest is calculated on principal plus previously earned interest, so growth accelerates over time compared with simple interest.
Can I use this in different currencies?
Yes. Pick USD, EUR, GBP, INR, AED, or another supported code in the currency picker. The formula does not change with currency.
What is effective annual rate (APY) here?
APY / EAR converts your nominal annual rate and compounding frequency into an equivalent once-per-year rate: (1 + r/n)^n − 1. It helps compare products that compound on different schedules.
Can I include monthly or yearly contributions?
Yes. Open Advanced options, choose Monthly or Yearly under Regular deposits, and enter the deposit amount. For a pure monthly-investing view, also try the SIP calculator.
How is time to double calculated?
Exact years = ln(2) / ln(1 + EAR) using the effective annual rate from your nominal rate and compounding. Rule of 72 (72 ÷ rate%) is shown as a quick approximation. Both are principal-only — deposits change when the balance actually doubles.
How does this relate to EMI or mortgage payments?
Compound Interest grows savings; Loan / EMI and Mortgage amortize debt with the same reducing-balance family on the borrowing side. Open those tools when you are sizing a payment instead of a future value.
How is this different from SIP?
SIP is contribution-first monthly investing with an invested-vs-portfolio chart. This page emphasizes principal, compounding frequency, APY, RoR, time to double, and optional deposits.
Is this investment advice?
No. Educational illustration only. Confirm product terms with your bank or advisor.
What does the Compound Interest Calculator on MyCalcsWorld actually compute?
Project compound growth with optional regular deposits, effective APY, rate of return, time to double, chart, and yearly schedule. You enter Principal (money), Annual rate (%), Years (years), Compounded, Regular deposits, and the result panel updates in your browser — free, no signup. Below the form you will find when-to-use tips, common mistakes, a worked example, formula notes, and FAQs for this tool.
Questions about this tool? Contact MyCalcsWorld · mycalcsworldcontact