About Finance Calculation

This calculator supports both simple and compound interest, periodic contributions, tax and inflation adjustment, and provides a detailed accumulation schedule.

Simple Interest

Simple interest is calculated only on the original principal. It is commonly used for short-term loans and some consumer loans in the United States.

Formula: Interest = Principal × Rate × Time

Example: If you invest $1,000 at an annual interest rate of 5% for 3 years:
Interest = $1,000 × 5% × 3 = $150
Total Amount = $1,000 + $150 = $1,150

Compound Interest

Compound interest is calculated on the principal and also on the accumulated interest of previous periods. It is the standard for savings, investments, and many loans in Europe and worldwide.

Formula: Final Amount = Principal × (1 + Rate / n)n × t
where n is the number of compounding periods per year, and t is the number of years.

Example: If you invest $1,000 at an annual interest rate of 5% compounded monthly for 3 years:
n = 12
Final Amount = $1,000 × (1 + 0.05 / 12)^{12 × 3} ≈ $1,161.62
Total Interest = $1,161.62 - $1,000 = $161.62

Periodic Contributions

If you make regular contributions, the formula for the future value of a series of payments (ordinary annuity) is:
FV = P × (1 + r)nt + PMT × [((1 + r)nt - 1) / r]
where PMT is the periodic contribution, r is the periodic interest rate, n is the number of periods per year, and t is the number of years.

Parameters Explained

• PV: Present Value - The current value of the investment or loan.
• FV: Future Value - The value of the investment or loan at a future date.
• I/Y: Interest Rate - The annual interest rate expressed as a percentage.
• N: Number of Periods - The total number of payment periods.
• PMT: Periodic Payment - The regular payment amount made at each period.
• P/Y: Payments per Year - The number of payments per year.
• C/Y: Compounds per Year - The number of times interest is compounded per year.
• PMT at: PMT at - Whether the PMT is at the beginning or end of the period.

Tax and Inflation Adjustment

If you want to adjust for taxes and inflation, you can use the following formula:

Formula: Adjusted Value = Original Value × (1 + Inflation Rate) × (1 - Tax Rate)

Example: If you invest $1,000 at an annual interest rate of 5% for 3 years, and the inflation rate is 2% and the tax rate is 10%:
Adjusted Value = $1,000 × (1 + 0.02) × (1 - 0.10) = $909.09

Inflation Adjustment

If you want to adjust for inflation, you can use the following formula:

Formula: Adjusted Value = Original Value / (1 + Inflation Rate)t
where t is the number of years.

Example: If you invest $1,000 at an annual interest rate of 5% for 3 years, and the inflation rate is 2%:
Adjusted Value = $1,000 / (1 + 0.02)³ ≈ $942.32

Tax Adjustment

If you want to adjust for taxes, you can use the following formula:

Formula: Adjusted Value = Original Value × (1 - Tax Rate)

Example: If you invest $1,000 at an annual interest rate of 5% for 3 years, and the tax rate is 10%:
Adjusted Value = $1,000 × (1 - 0.10) = $900