How Interest Works on a Savings Account

Compound interest has a snowball effect

Interest on a savings account is the amount of money a bank or financial institution pays on your deposits. Compound interest is when interest is added to your deposit, then interest is calculated on that new higher amount.

Compound interest on a savings account is calculated on principal and earned interest from previous periods. Essentially your earnings are reinvested and future interest is earned on the higher amount.

Learn more about how interest on a savings account works, including how banks use your savings deposits to fund loans.

Key Takeaways

  • Banks state their savings interest rates as an annual percentage yield (APY), which includes compounding.
  • Compound interest is interest calculated on principal and earned interest from previous periods.
  • Simple interest is only calculated based on principal.  
  • Interest compounded over a long enough time period can help your savings grow faster.

Savings account interest rates can help you grow your money. A bank essentially borrows money from their depositors by using the deposited funds to lend money to other customers. In turn, the bank pays the depositor interest for their savings account balance while simultaneously charging their loan customers a higher interest rate than what was paid to their depositors.

If you reinvest the interest you earned on your savings account and the initial amount deposited, you'll earn even more money in the long term.

Compounding is when you earn interest on your savings plus interest on all of the accumulated interest from previous periods. You can use the concept of compounding interest to build up your savings and create wealth.

Interest on savings accounts is expressed in percentage terms. For example, let's say you have $1,000 in the bank. The account might earn 2.5% interest. Most banks paid less than 1% interest on savings accounts in the between 2021 and 2022 due to historically low interest rates. However, in March 2022, the Fed began raising rates after a two-year period of near-zero interest rates.

Compounding Interest

In a straightforward interest calculation, $1,000 in a savings account that earns 1% interest in one year would yield $1,010 (or .01 x 1,000) at the end of the year. However, that calculation is based on simple interest, paid only on the principal or the deposited funds.

Some investors, such as retirees, might withdraw the earned interest or transfer it to another account. The interest payments act as a form of income. If the interest is withdrawn, the depositor's account will earn simple interest since no interest would be earned on any past interest.

However, some depositors may opt to leave the interest earned in their savings accounts to earn more interest.

How Interest Works on Savings Accounts

Investopedia / Yurle Villegas

The Power of Compounding Interest

In savings accounts, interest can be compounded, either daily, monthly, or quarterly. The more frequently interest is added to your balance, the faster your savings will grow.

Using an example of a $1,000 deposit and applying daily compounding every day, the amount that earns interest grows by another 1/365th of 1%. At the end of the year, the deposit would grow to $1,010.05 versus $1,010 via simple interest.

Of course, an extra $0.05 doesn't sound like much, but at the end of 10 years, your $1,000 would grow to $1,105.17 with compound interest. The 1% interest rate, compounded daily for 10 years, has added more than 10% to the value of your investment.

Again, the amount earned still might not seem like much, but consider what would happen if you could save $100 a month and add it to the original $1,000 deposit. After one year, you would have earned $16.05 in interest, for a balance of $2,216.05. After 10 years, still adding just $100 a month, you would have earned $725.50, for a total of $13,725.50.

Total Compounded Savings in 10 Years
Year Future Value at 1% Total Contributions
Year 0 $1,000 $1,000
1 $2,216.05 $2,200
2 $3,444.33 $3,400
3 $4,684.95 $4,600
4 $5,938.03 $5,800
5 $7,203.72 $7,000
6 $8,482.12 $8,200
7 $9,773.37 $9,400
8 $11,077.59 $10,600
9 $12,394.93 $11,800
10 $13,725.50 $13,000
Obtained via interest calculator from Investor.gov.

A savings account can keep your assets safe from fluctuations in the stock market and real estate values. It's essentially an emergency fund that can be used for unexpected expenses such as medical bills or car repairs. The money in a savings account is considered more liquid than money in other accounts like CDs because you can access it quickly.

Keep in mind that savings accounts, while a safe place for your money, tend to offer lower rates of return than investing in assets like stocks or bonds.

How Savings Account Interest Builds Wealth

Compound interest can build wealth over time, even when interest rates are at rock bottom. If you're considering opening an account, you can find the current rates banks online. Some banks specialize in high-yield savings accounts.

The best savings accounts include those offered by banks where interest on the account is compounded daily, and no monthly fees are charged. Banks often state their interest rates as annual percentage yield (APY), reflecting the effects of compounding.

The APY and annual percentage rate (APR) are not the same. The APR doesn't include compounding.

Frequently Asked Questions (FAQs)

How Is Savings Account Interest Calculated?

To calculate simple interest on a savings account, you'll need the account's APY and the amount of your balance. The formula for calculating interest on a savings account is: Balance x Rate x Number of years = Simple interest.

What's Compound Interest Compared With Simple Interest?

Compound is interest on your interest, or reinvesting accumulated interest from previous periods. Simple interest is paid only on the principal or the deposited funds.

What's the Long-Term Benefit of Compounding?

Investors can use the concept of compounding interest to build up their savings and create wealth. If you reinvest the interest you earned on your savings account and the initial amount deposited, you'll earn even more money in the long term.

How Often Is Interest Compounded?

Depending on the type of account or product, interest is typically compounded monthly, quarterly, or annually. Interest can also be compounded weekly or daily.

The Bottom Line

Putting your money in a savings account that earns interest can help you build wealth faster while protecting your money. Understanding how interest works on a savings account and how to compare different interest rates can help you choose the best savings account for you. Consider consulting with a professional financial advisor on how to best budget for your financial goals.

Article Sources
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
  1. State of Connecticut, Department of Banking. "ABC's of Banking."

  2. Federal Deposit Insurance Corporation. "National Rates and Rate Caps - Previous Rates; Revised Rule April 1, 2021."

  3. Federal Deposit Insurance Corporation. "National Rates and Rate Caps; Revised Rule July 18, 2022."

  4. Federal Reserve Bank of St. Louis, FRED. "Effective Federal Funds Rate."

  5. Federal Insurance Deposit Corporation. "National Rates and Rate Caps."

  6. Aswath Damodaran. "Historical Returns on Stocks, Bonds and Bills: 1928-2023." New York University, Stern School of Business.

  7. Consumer Financial Protection Bureau. "12 CFR Part 1026 (Regulation Z); §1026.14 Determination of Annual Percentage Rate."

  8. Consumer Financial Protection Bureau. "12 CFR Part 1030 (Regulation DD); Appendix A to Part 1030 — Annual Percentage Yield Calculation."

Part of the Series
Guide to Savings Accounts
Open a New Bank Account
×
The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.