How to Calculate Interest in a Savings Account
In a world where it can seem hard to make and stretch a dollar (hello, inflation!), isn’t it nice to know that there’s a way to earn money without any effort? That would be by collecting interest on a savings account. Your financial institution pays you for the privilege of using the cash you have on deposit, pumping up your wealth without the least bit of work on your part.
Knowing how to calculate interest can help you more effectively compare savings accounts. It also helps you understand exactly how much money you can earn on your money over time by keeping it in the account. What follows is a simple guide to how interest on savings accounts works.
Key Points
• Understanding interest helps individuals compare savings accounts and determine potential earnings, enhancing their financial decision-making process.
• Simple interest is calculated using the formula: Simple Interest = Principal x Rate x Time, allowing for straightforward calculations of earnings.
• Compound interest accelerates wealth growth by allowing interest to earn interest, thereby increasing the principal over time and enhancing overall returns.
• The annual percentage yield (APY) simplifies the comparison of different savings accounts by incorporating both the interest rate and the effects of compounding into a single rate of return.
• Various factors, including Federal Reserve rates and promotional offers, influence the interest rates banks provide, making it essential to shop around for the best savings account.
What Is Interest?
Interest is the amount of money that a bank pays a depositor for storing money at their institution. While the money you have on deposit remains accessible to you, the bank uses that money for other purposes, such as lending it out for a mortgage loan. One way banks can make money is via the differential between the interest they pay for money on deposit (say, 3%) and the interest they charge when someone else borrows it (say, 6% on a home loan).
Simple Interest Formula
Calculating interest on a savings account involves some not-too-complex math; in fact, it’s primarily multiplication you need to use. The formula for simple interest looks like this:
Simple Interest = P x R x T
Where:
• P stands for the principal, or the amount on deposit.
• R stands for the interest rate, expressed as an annual rate usually, in decimal form.
• T stands for time, or how long the money is held by the bank.
How Do You Calculate Interest in a Savings Account?
Now, consider how this formula could be used to calculate the interest earned on savings you deposit at a financial institution.
If you deposited $5,000 in a bank for one year at a 3.00% interest rate, the simple interest after one year would be, using the PxRxT formula:
5,000 x .03 x 1 = $150
So, by calculating savings interest, you see that you’ve earned $150. To put it another way, at the end of one year, your $5,000 would have grown to $5,150.
This, of course, represents simple interest. When putting your money in the bank today, you may well earn compound interest.
Simple vs Compound Interest
When you earn interest on the principal amount alone, such as in the example above, it’s called “simple interest.”
But the reason savings accounts can be such an effective tool for growing money is that not only is interest earned on the amount deposited, but the interest also earns interest. This is called compounding.
Depending on the account, interest may be calculated and added (or compounded) daily, monthly, or quarterly. Each time this happens, the interest earned to date becomes part of the principal, and the interest earned moving forward will be based on both the principal plus the interest earned to date. You might think of it as accelerating your money’s growth as time passes.
Example
Here’s what compound interest looks like in action, using the same $5,000 initial deposit, but a 3.00% interest that compounds on a monthly basis.
• After one month, the account would have $5,000 plus interest totalling one-twelfth of the 3.00% annual interest, or $12.50.
• The next month, the interest would be calculated on $5,012.50 ($5,012.50 plus $12.53). The month after that, the interest would be calculated on $5,025.03, and so on.
• At the end of one year, the account would have $5,152.08.
• After 10 years, monthly compounding will grow that initial $5,000 to $6,746.77, without adding a single penny more to the account.
With simple interest, you would only earn 3.00% on the original amount ($5,000) each year, or $150. With compounding, you earn interest on your principal plus any interest you’ve already earned.
Here’s a chart showing the difference simple vs. compound interest can make at a rate of 3.00% on $5,000 deposit:
Time | Simple Interest | Interest Compounded Monthly |
---|---|---|
Account opened | $5,000 | $5,000 |
1 year | $5,150 | $5,152.08 |
5 years | $5,750 | $5,808.08 |
10 years | $6,500 | $6,746.77 |
20 years | $8,000 | $9,103.77 |
It may not seem like compounding could make a huge difference, but adding to the principal regularly can grow your money faster. In addition, seeking out a higher interest rate can of course boost your cash faster as well.
APY vs Monthly Interest Rate
Calculating compound interest can get complex; the equation involves more complicated math. But some banks simplify an account holder’s potential earnings into a single rate called the annual percentage yield, or APY. The APY factors in both the interest rate and the effect of compounding into an actual rate of return over the course of one year. To calculate how much interest will be earned on a savings account using the APY, simply multiply the principal by the APY.
This simplicity makes APY a more helpful rate to use when comparing interest rates for different accounts or banks, because it includes the effect of compounding. Banks will usually post this information because the APY is higher than the stated interest rate. A savings account interest calculator can be helpful when calculating how much interest you’ll earn over multiple years. It also allows you to see how adding to your savings account each month can impact your earnings.
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Understanding Interest Rates
In comparing savings accounts at different banks (or even within the same bank), consumers may notice that interest rates can vary with the type of account. What’s more, interest rates posted by the Federal Reserve (aka “the Fed”) may vary considerably from the interest rates banks offer their customers.
Tasked with maintaining economic stability, the Fed uses signals such as employment data and inflation to determine its rates. During economic slowdowns, the Fed typically lowers rates to reduce the cost of borrowing and incentivize individuals and businesses to spend more, stimulating the economy. Conversely, when the economy appears to be growing too quickly, the Fed may raise rates, increasing the cost of borrowing in order to slow spending.
How does this play into the interest rate consumers might earn on their own savings? There are a number of factors that determine the interest rate a bank posts:
• The target federal funds rate, set by the Fed, is one such cue.
• Banks, however, set their own interest rates and these may vary depending on factors such as promotions the bank may have in place to attract new customers or incentivize greater account balances, as well as how much work an account takes to administer.
This last factor is why checking accounts, which are often used for a higher volume of everyday transactions, often pay less interest than savings accounts, where customers are more likely to let their money sit and accrue.
• Interest rates also change over time, so the posted rate when an account is opened may not remain the same.
• Banks may also have tiered interest rates, where account holders earn different rates of interest depending how much they have in their account, or balance caps, in which an interest rate can only be earned up to a certain amount.
Recommended: Basics of a High-Yield Savings Account
What Is a Good Savings Account Interest Rate?
What is a good savings account interest rate will vary with the times. During the 1980s, the interest rates on savings accounts were around 8.00%, while from 2018 to 2021, the average was barely one-tenth of one percent, which could hardly keep pace with inflation.
As you shop around for the right account at the right rate, you may find that online banks offer some of the most competitive APYs. Since they don’t have brick-and-mortar locations, they can pass their savings on to their customers. Savings account rates are averaging 0.41% APY as of December 16, 2024, according to the FDIC. A high-yield account at an online bank, however, may pay 3.00% APY or higher.
Questions to Ask When Considering a Savings Account
It’s hard to dispute the appeal of earning money on savings. But in addition to knowing how to calculate interest on a savings account, there are other considerations that could affect the flexibility and ease with which that account will help you achieve your goals. Some account holders may find they need multiple bank accounts to meet both their everyday and long-term financial needs and goals.
Here are some things to consider.
Will You Be Penalized for Everyday Transactions?
Savings accounts typically provide higher interest rates than checking accounts because they require less work for the bank to administer since they’re not meant to be used for everyday transactions.
But savings accounts may limit the number of transactions you can make in a month, and charge a fee if you exceed the limit. The Federal Reserve’s Regulation D, which imposed a six-transaction-per-month limit, was loosened during the COVID-19 pandemic. Even so, some banks have opted to continue to impose limits on savings account transactions to six or, sometimes, nine per month. Inquire at a potential new home for your funds before opening a savings account.
Is There a Minimum Balance?
Some banks incentivize or penalize customers to encourage them to keep more money in their accounts. For example, an account may be subject to fees unless the balance is maintained above a certain amount. Tiered savings accounts provide a higher rate of interest on bank balances above certain levels.
Can the Money Be Accessed Easily?
Some types of savings accounts provide higher interest rates but limit access to your money for a predetermined earnings period. For example, a certificate of deposit (CD) is a savings vehicle that holds an investor’s money for a certain period of time. At the end of that term, the account holder is paid the original principal plus the interest earned. There may be penalties imposed on early withdrawals from a CD.
Can the Account Help Achieve Money Goals?
Earning interest is a key way a savings account can help you achieve your financial goals. If you’re saving for multiple goals at the same time — say building your emergency fund and saving for an upcoming vacation — it can be helpful to be able to know at a glance how much progress you’re making towards each goal. At some banks, you might need to open separate accounts to track each savings goal, while others may provide tools to organize your savings goals within a single account.
The Takeaway
The easiest way to calculate how much interest you’ll earn on a savings account is to multiply the account’s APY by your balance. This tells you what you’ll earn on your money over one year if you don’t make any withdrawals or deposits during that time. An online APY calculator makes it easy to calculate how much interest you’ll earn in a savings account over multiple years, taking your bank’s compounding frequency into account.
When shopping for a savings account, it’s important to not only compare APYs but also read the find print to find out if there are any balance requirements to earn the advertised APY and/or any fees that could eat into your earnings.
Interested in opening an online bank account? When you sign up for a SoFi Checking and Savings account with direct deposit, you’ll get a competitive annual percentage yield (APY), pay zero account fees, and enjoy an array of rewards, such as access to the Allpoint Network of 55,000+ fee-free ATMs globally. Qualifying accounts can even access their paycheck up to two days early.
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SoFi members with direct deposit activity can earn 3.80% annual percentage yield (APY) on savings balances (including Vaults) and 0.50% APY on checking balances. Direct Deposit means a recurring deposit of regular income to an account holder’s SoFi Checking or Savings account, including payroll, pension, or government benefit payments (e.g., Social Security), made by the account holder’s employer, payroll or benefits provider or government agency (“Direct Deposit”) via the Automated Clearing House (“ACH”) Network during a 30-day Evaluation Period (as defined below). Deposits that are not from an employer or government agency, including but not limited to check deposits, peer-to-peer transfers (e.g., transfers from PayPal, Venmo, etc.), merchant transactions (e.g., transactions from PayPal, Stripe, Square, etc.), and bank ACH funds transfers and wire transfers from external accounts, or are non-recurring in nature (e.g., IRS tax refunds), do not constitute Direct Deposit activity. There is no minimum Direct Deposit amount required to qualify for the stated interest rate. SoFi members with direct deposit are eligible for other SoFi Plus benefits.
As an alternative to direct deposit, SoFi members with Qualifying Deposits can earn 3.80% APY on savings balances (including Vaults) and 0.50% APY on checking balances. Qualifying Deposits means one or more deposits that, in the aggregate, are equal to or greater than $5,000 to an account holder’s SoFi Checking and Savings account (“Qualifying Deposits”) during a 30-day Evaluation Period (as defined below). Qualifying Deposits only include those deposits from the following eligible sources: (i) ACH transfers, (ii) inbound wire transfers, (iii) peer-to-peer transfers (i.e., external transfers from PayPal, Venmo, etc. and internal peer-to-peer transfers from a SoFi account belonging to another account holder), (iv) check deposits, (v) instant funding to your SoFi Bank Debit Card, (vi) push payments to your SoFi Bank Debit Card, and (vii) cash deposits. Qualifying Deposits do not include: (i) transfers between an account holder’s Checking account, Savings account, and/or Vaults; (ii) interest payments; (iii) bonuses issued by SoFi Bank or its affiliates; or (iv) credits, reversals, and refunds from SoFi Bank, N.A. (“SoFi Bank”) or from a merchant. SoFi members with Qualifying Deposits are not eligible for other SoFi Plus benefits.
SoFi Bank shall, in its sole discretion, assess each account holder’s Direct Deposit activity and Qualifying Deposits throughout each 30-Day Evaluation Period to determine the applicability of rates and may request additional documentation for verification of eligibility. The 30-Day Evaluation Period refers to the “Start Date” and “End Date” set forth on the APY Details page of your account, which comprises a period of 30 calendar days (the “30-Day Evaluation Period”). You can access the APY Details page at any time by logging into your SoFi account on the SoFi mobile app or SoFi website and selecting either (i) Banking > Savings > Current APY or (ii) Banking > Checking > Current APY. Upon receiving a Direct Deposit or $5,000 in Qualifying Deposits to your account, you will begin earning 3.80% APY on savings balances (including Vaults) and 0.50% on checking balances on or before the following calendar day. You will continue to earn these APYs for (i) the remainder of the current 30-Day Evaluation Period and through the end of the subsequent 30-Day Evaluation Period and (ii) any following 30-day Evaluation Periods during which SoFi Bank determines you to have Direct Deposit activity or $5,000 in Qualifying Deposits without interruption.
SoFi Bank reserves the right to grant a grace period to account holders following a change in Direct Deposit activity or Qualifying Deposits activity before adjusting rates. If SoFi Bank grants you a grace period, the dates for such grace period will be reflected on the APY Details page of your account. If SoFi Bank determines that you did not have Direct Deposit activity or $5,000 in Qualifying Deposits during the current 30-day Evaluation Period and, if applicable, the grace period, then you will begin earning the rates earned by account holders without either Direct Deposit or Qualifying Deposits until you have Direct Deposit activity or $5,000 in Qualifying Deposits in a subsequent 30-Day Evaluation Period. For the avoidance of doubt, an account holder with both Direct Deposit activity and Qualifying Deposits will earn the rates earned by account holders with Direct Deposit.
Separately, SoFi members who enroll in SoFi Plus by paying the SoFi Plus Subscription Fee every 30 days can also earn 3.80% APY on savings balances (including Vaults) and 0.50% APY on checking balances. For additional details, see the SoFi Plus Terms and Conditions at https://www.sofi.com/terms-of-use/#plus.
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