This tutorial explains how to calculate compound interest in Excel, providing examples for annual, monthly, and daily compounding. You'll learn to build your own Excel compound interest calculator.

Compound interest, a fundamental concept in finance, significantly impacts investment growth. While complex for non-finance professionals, this guide simplifies the process. You'll also learn to create a versatile compound interest calculator for your spreadsheets.

What is Compound Interest?

Simply put, compound interest is interest earned on both the principal and accumulated interest. Unlike simple interest, calculated solely on the principal, compound interest increases the principal with each compounding period. For example, $10 invested at 7% annual interest yields $10.70 after one year. With compound interest, that $0.70 is added to the principal, earning interest in subsequent years.

Calculating Compound Interest in Excel

Long-term investments benefit greatly from compounding. Excel formulas can effectively model this growth. We'll build a formula adaptable to various compounding frequencies.

Calculating Annual Compound Interest in Excel

Let's start with a simple example: $10 invested at 7% annual interest.

Formula 1: A straightforward approach uses the formula =Amount * (1 %). For a $10 investment (A2) and 7% interest (B2), the formula is =A2*(1 $B2). This calculates the balance after one year. Repeating this formula for subsequent years demonstrates the compounding effect.

Formula 2: Alternatively, calculate yearly interest and add it to the previous year's balance. With initial deposit in B1 and interest rate in B2, the formula for year 1 is =B1 B1 * $B$2. For subsequent years (e.g., B6), use =B5 B5 * $B$2. This method clearly shows the interest earned each year.

These examples illustrate the concept, but lack flexibility in compounding frequency. Let's create a more versatile formula.

General Compound Interest Formula

The future value (FV) of an investment is determined by:

• PV: Present value (initial investment)
• i: Interest rate per period
• n: Number of periods

The formula is: FV = PV * (1 i)ⁿ

Example: Monthly Compounding

$2,000 invested at 8% annual interest, compounded monthly for 5 years:

PV = $2,000 i = 0.08/12 (monthly interest rate) n = 5 * 12 (number of months)

FV = $2,000 * (1 0.08/12)⁶⁰ = $2,979.69

Excel Compound Interest Formula (Daily, Monthly, Yearly)

We'll create an Excel calculator with:

• Initial investment
• Annual interest rate
• Compounding periods per year
• Number of years

The formula is: =Initial Investment * (1 Annual Interest Rate / Compounding Periods) ^ (Years * Compounding Periods)

This formula adapts to different compounding frequencies (daily, weekly, monthly, etc.) by changing the "Compounding Periods" input.

Advanced Excel Compound Interest Calculator

Excel's FV function offers another approach: FV(rate, nper, pmt, [pv], [type]).

Using the monthly compounding example: =FV(0.08/12, 5*12, ,-2000) (pv is negative for outflow). This provides the same result.

This can be enhanced by adding optional additional contributions.

Online Compound Interest Calculators

Several online calculators simplify compound interest calculations. Bankrate, Money-Zine, and MoneySmart offer user-friendly interfaces with varying features.

This tutorial provides both manual and Excel-based methods for compound interest calculations, empowering you to manage your investments effectively. A downloadable Excel workbook is available.

The above is the detailed content of Calculate compound interest in Excel: formula and calculator. For more information, please follow other related articles on the PHP Chinese website!