DocomintCalculadora de Juros Compostos
Calcule o valor futuro de um investimento com juros compostos, de diário a anual.
What is a Calculadora de Juros Compostos?
Compound interest earns interest on top of previously earned interest, not just the original principal — the more frequently it compounds (daily vs. annually), the faster it grows, since each compounding period's gains start earning their own interest sooner.
How to use the Calculadora de Juros Compostos
- Enter the principal, annual interest rate, compounding frequency, and years
- Press Calculate
- The future value and total interest earned appear instantly, computed on your device
Formula
A = P × (1 + r/n)^(n×t)
P is principal, r is the annual rate as a decimal, n is compounds per year, and t is time in years — the exponent's n×t is the total number of compounding periods over the full timeframe.
Example
$10,000 at 6% annual interest compounded monthly for 10 years grows to about $18,194 — compare that to the same principal and rate under Simple Interest Calculator, which only reaches $16,000, to see exactly how much compounding itself contributes.
Common mistakes
- Entering the interest rate as a decimal (0.06) instead of a whole percentage (6) — the field expects the percentage figure.
- Leaving compounding frequency on its default when the actual product compounds differently — the frequency meaningfully changes the result.
- Comparing this directly against Simple Interest Calculator's output using the same numbers and expecting an identical result — they diverge more with time and higher rates.
Frequently asked questions
How does compounding frequency affect growth?
More frequent compounding (daily vs. monthly vs. annually) means interest starts earning its own interest sooner, so the same nominal annual rate produces slightly more growth the more often it compounds — though the difference between, say, monthly and daily compounding is usually small in practice.
What's the difference between compound and simple interest?
Simple interest is calculated only on the original principal every period. Compound interest is calculated on the principal plus all interest already earned, so growth accelerates over time rather than staying linear.
Does this include regular contributions, like a deposit every month?
No — this projects growth of a single lump-sum principal only. For a starting balance plus ongoing monthly contributions, see Savings Goal Calculator or Retirement Calculator instead.
What's a realistic interest rate to use?
It depends entirely on the account or investment — a savings account might pay low single digits, while a diversified stock portfolio has historically averaged higher over long periods, with far more year-to-year variability. Use the actual rate quoted for your specific product where possible.
Is my numbers uploaded anywhere?
No — Calculadora de Juros Compostos runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.