Help & Guide – Compound Interest Explained

Compound interest is the interest calculated on the initial principal and also on the accumulated interest of previous periods. It creates a snowball effect over time.

• Initial Amount: Your starting investment.
• Annual Interest Rate: Input yearly rate (e.g. 5 for 5%).
• Years: Total investment duration. Supports decimals.
• Times Compounded Per Year: 12 = monthly, 4 = quarterly, etc.
• Recurring Contribution: Optional amount you add regularly.
• Contribution Frequency: How many times you add per year.

Total Amount = Principal Growth + Recurring Growth

Principal Growth:

P × (1 + r / n) ^ (n × t)

Recurring Contribution Growth:

PMT × [(1 + r / m) ^ (m × t) - 1] / (r / m)

Parameters:

• P: Initial Principal
• r: Annual Interest Rate (decimal)
• n: Compounding Frequency
• m: Contribution Frequency
• t: Years
• PMT: Contribution Amount

• Use decimals for partial years (e.g. 1.5 = 18 months).
• Set compounding and contribution frequency both to 12 for monthly.
• Click "Calculate" after entering your inputs to see result.
• Use "Clear" to reset all fields.