Smart Money Basics
Home / Calculators

Calculators

Six free tools to run your own numbers. Everything is calculated in your browser: nothing you type is saved or sent anywhere. Results are estimates for education, not advice.

Investment growth calculator

See how a starting balance plus regular contributions could grow, assuming a steady annual return compounded monthly.

Balance at the end
—
Total you put in
—
Growth
—

A hypothetical illustration, not a prediction or a promise. Real returns change every year and can be negative. It ignores taxes, fees and inflation.

Debt payoff calculator

See how long one debt takes to pay off with a fixed monthly payment, and how much interest it costs.

Time to pay off
—
Total interest
—
Total you pay
—

Assumes a fixed rate and no new charges. Your lender's statement is the final word on what you owe.

50/30/20 budget calculator

Enter your monthly take-home pay (after taxes). The percentages start at 50/30/20 and you can change them.

Needs
—
Wants
—
Savings and extra debt payments
—

A starting framework, not a rule. Adjust the percentages to your cost of living.

Emergency fund calculator

Work out a target and how long it could take to reach it.

Your target
—
Still to save
—
Time to reach it
—

How much is right depends on your situation. Even a small cushion helps.

APR to APY calculator

Convert a stated annual rate into the effective yearly rate after compounding.

APY
—
Interest on $10,000 after one year
—
Extra compared with the stated rate
—

Savings accounts usually advertise APY. Loans and credit cards advertise APR.

Inflation calculator

See how inflation can erode what an amount of money buys over time.

What it could buy, in today's dollars
—
Purchasing power lost
—
Future price of something that costs this amount today
—

The 3% default is only an example. Actual inflation changes from year to year.

Want to understand the formulas? Start with how compound interest works and APR vs. APY.