Step 1: How to use this calculator?

{'step': 1, 'description': 'Convert annual rate to periodic rate', 'calculation': '6.5% ÷ 12 = 0.5417% per month'}

Step 2: How to use this calculator?

{'step': 2, 'description': 'Calculate total compounding periods', 'calculation': '15 years × 12 = 180 months'}

Using simples interest instead of compound interest for long-term projections

Forgetting that more frequent compounding increases returns slightly

Calculadora de Juros Compostos

Last updated: 2026-08-24

Calculadora de Juros Compostos — Calcule o crescimento de um investimento com juros compostos.

Inputs

Result

Enter values and press Calculate

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How to use it

{'step': 1, 'description': 'Convert annual rate to periodic rate', 'calculation': '6.5% ÷ 12 = 0.5417% per month'}
{'step': 2, 'description': 'Calculate total compounding periods', 'calculation': '15 years × 12 = 180 months'}
{'step': 3, 'description': 'Apply compound interest formula', 'calculation': '€5,000 × (1 + 0.065/12)^(12×15) = €13,233.52'}
{'step': 4, 'description': 'Calculate total interest earned', 'calculation': '€13,233.52 - €5,000 = €8,233.52'}

Common mistakes

⚠️ Using simples interest instead of compound interest for long-term projections
⚠️ Forgetting that more frequent compounding increases returns slightly
⚠️ Not accounting for inflation eroding purchasing power over time

Worked example

Projecting growth of €5,000 investment at 6.5% annual return compounded monthly over 15 years.

Your capital_final of {capital_final} shows the future value after {anos} years. The multiplicador of {multiplicador}x shows how many times your money grew.

Input guide

Field	Typical range
frecuencia_anual	1-365 times per year (annual to daily)
anos	1-40 years investment horizon
capital_inicial	€100 - €500,000 initial investments
interes_anual_pct	3-12% typical investment returns