What is compound interest?

Compound interest is interest calculated on both the initial principal and the previously accumulated interest. Unlike simple interest, it grows exponentially over time.

How often should interest compound?

The more frequently interest compounds (daily > monthly > quarterly > annually), the more you earn. Daily compounding yields slightly more than monthly, which is better than annual.

What is the Rule of 72?

Divide 72 by your interest rate to estimate how many years it takes to double your money. At 7%, your money doubles in about 10.3 years.

What is the Rule of 72?

The Rule of 72 is a quick mental shortcut: divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 7%, money doubles in roughly 72 ÷ 7 ≈ 10.3 years. It's not exact but surprisingly accurate for rates between 4–12%.

Does compound interest work against you in debt?

Yes. The same math that grows savings also grows debt. Credit card debt at 20% APR: $5,000 left unpaid grows to over $30,000 in 10 years. The key difference is direction — in savings, time is your ally; in debt, time works against you. Paying off high-interest debt first often beats investing, purely on a risk-adjusted return basis.

Calculadora de Juros Compostos

Calcule como seu dinheiro cresce com juros compostos ao longo do tempo.

Valor Inicial

Contribuição Mensal

Taxa de Juros Anual

Período

anos

Frequência de Capitalização

Saldo Final

$54,915.51

Principal$10,000.00

Contribuições Totais$24,000.00

Total depositado$34,000.00

Juros Ganhos$20,915.51

Retorno Total61.52%

Ano 1$13,215.88 ($12,400.00 + $815.88 interest)

Ano 2$16,664.23 ($14,800.00 + $1,864.23 interest)

Ano 3$20,361.86 ($17,200.00 + $3,161.86 interest)

Ano 4$24,326.80 ($19,600.00 + $4,726.80 interest)

Ano 5$28,578.36 ($22,000.00 + $6,578.36 interest)

Ano 6$33,137.26 ($24,400.00 + $8,737.26 interest)

Ano 7$38,025.74 ($26,800.00 + $11,225.74 interest)

Ano 8$43,267.59 ($29,200.00 + $14,067.59 interest)

Ano 9$48,888.39 ($31,600.00 + $17,288.39 interest)

Ano 10$54,915.51 ($34,000.00 + $20,915.51 interest)

At 7.00% annual interest compounded Mensalmente with $200.00/month contributions, $10,000.00 grows to $54,915.51 in 10 anos — earning $20,915.51 in interest.

Análise E Se

Taxa de Juros Anual$54,915.51

Período$54,915.51

Starting 10 years earlier typically doubles your final balance. Time beats rate every time.

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Retirement Savings Calculator

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Sobre esta Calculadora

Juros compostos significa ganhar juros sobre o capital inicial E sobre os juros já acumulados. Esse efeito de "juros sobre juros" faz a riqueza crescer exponencialmente. Quanto mais tempo seu dinheiro fica investido, mais dramático é o crescimento.

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Perguntas Frequentes

O que são juros compostos?

Juros compostos são calculados sobre o capital inicial e sobre os juros acumulados anteriormente. Ao contrário dos juros simples, crescem exponencialmente.

Com que frequência os juros devem ser compostos?

Quanto mais frequente (diário > mensal > trimestral > anual), mais você ganha. A composição diária rende um pouco mais que a mensal.

O que é a regra dos 72?

Divida 72 pela sua taxa de juros para estimar em quantos anos seu dinheiro dobra. A 7%, seu dinheiro dobra em cerca de 10,3 anos.

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Leitura relacionada

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The Rule of 72 Explained — Mental Math Every Investor Should Know

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For informational purposes only. Calculator results are estimates based on the inputs you provide. This is not financial, investment, tax, or legal advice. Consult a qualified financial professional before making major financial decisions.