How much your $30,000 will earn depends on the interest rate and how long you leave it untouched
A $30,000 deposit earning 4.5% APY for one year generates about $1,350 in interest. At 0.01% APY (the rate many big banks offer), the same deposit earns roughly $3 per year. The difference between these two scenarios is $1,347 — the cost of not shopping around. Your actual earnings depend on three things: the rate your bank or credit union pays, how long the money sits, and whether interest compounds daily or monthly.
The math is straightforward. Multiply your balance by the APY, divide by 12 if you want a monthly estimate, and divide by 365 if you want a daily one. But the real question is not what the math says — it is which account actually pays that rate, and whether you can access it without jumping through hoops.
Key Takeaways
- A $30,000 deposit at 4.5% APY earns roughly $1,350 per year; at 0.01% it earns about $3 per year.
- Online banks and credit unions typically pay 4% to 5.35% APY on savings accounts, while traditional brick-and-mortar banks often pay less than 0.1%.
- Interest compounds daily at most banks, meaning you earn interest on your interest, though the effect is small on a one-year timeline.
- Rates change frequently and vary by account type, so the rate you see today may not be the rate you lock in tomorrow.
Earnings at common savings account rates
Here is what $30,000 earns over one year at rates you will actually see offered:
| APY Rate | Annual Interest Earned | Monthly Average | Where you might find it |
|---|---|---|---|
| 0.01% | $3 | $0.25 | Large national banks |
| 0.5% | $150 | $12.50 | Some regional banks |
| 2.0% | $600 | $50 | Older online bank offers |
| 4.5% | $1,350 | $112.50 | Current online banks and credit unions |
| 5.35% | $1,605 | $133.75 | Top-paying online banks |
These rates change. The 5.35% figure was accurate in early 2024, but by the time you read this, the highest rates may have shifted up or down depending on what the Federal Reserve does with its benchmark rate. Check the current rates at the banks you are considering before you move money.
The difference between 4.5% and 5.35% on $30,000 is $255 per year. That is not life-changing, but it is real money for doing nothing except choosing the right account. The difference between 0.01% and 4.5% is $1,347 per year — enough to matter.
How compounding affects your total
Most savings accounts compound interest daily, meaning the bank calculates what you owe every day and adds it to your balance. The next day, you earn interest on that slightly larger balance. Over a year, this compounds to a small boost above the simple calculation.
On $30,000 at 4.5% APY with daily compounding, you earn about $1,354 instead of $1,350. The difference is $4. It matters more if you leave the money for five or ten years, but for a one-year horizon, compounding is a rounding error. What matters far more is picking an account that pays 4.5% instead of 0.01%.
Some accounts compound monthly instead of daily. This reduces your earnings slightly — perhaps by $1 to $2 on a $30,000 balance over a year. When you are comparing accounts, daily compounding is better, but it is a smaller factor than the base rate itself.
Why rates vary so much between banks
A large national bank with thousands of branches pays less interest because it does not need to compete for deposits. People keep money there for convenience, not yield. An online bank with no physical locations must pay more to attract deposits, because the only reason to bank there is the rate.
Credit unions often pay higher rates than banks because they are member-owned and return profits to account holders rather than shareholders. You need to join the credit union (usually by opening a savings account or meeting a membership requirement), but once you do, the rates are often competitive with online banks.
The Federal Reserve's benchmark rate also drives the market. When the Fed raises rates, banks raise what they pay on savings. When the Fed cuts rates, savings rates fall. This happens with a lag — sometimes weeks or months — so the highest rate available today may not be the highest rate available in three months.
How long you keep the money matters
If you leave $30,000 in a 4.5% APY account for five years, you earn roughly $7,090 in total interest (accounting for daily compounding). Over ten years, you earn about $14,936. The longer the money sits, the more compounding works in your favor, though the base rate is still the dominant factor.
If you need the money in six months, you earn about $675 at 4.5% APY. If you need it in three months, you earn about $338. The math is simple: take the annual interest, divide by 12, and multiply by the number of months. Most banks pay interest on partial years, so you do not lose anything by withdrawing early — you just earn less because the money was there for less time.
Checking accounts and money market accounts pay differently
A traditional checking account pays almost nothing — often 0.01% or less. A money market account (sometimes called a money market savings account) typically pays more than a regular savings account but may have higher minimum balances or limits on how many times you can withdraw per month.
On $30,000, a money market account paying 4.75% earns about $1,425 per year, compared to $1,350 at a regular savings account paying 4.5%. The difference is $75 per year. Whether that is worth the restrictions depends on whether you need frequent access to the money. If you are setting this aside and not touching it, a regular savings account is simpler and the rate difference is usually small.
What to do before you move your money
Check the current rates at three to five banks or credit unions. Rates change weekly, so the rate you see today may not be locked in when you transfer the money. Some banks advertise a high rate for new deposits only, then drop it after a few months — read the fine print.
Confirm that the bank or credit union is FDIC-insured (banks) or NCUA-insured (credit unions). This protects your deposit up to $250,000 if the institution fails. Most online banks and credit unions carry this protection, but verify it on their website before you move money.
Look at the minimum balance requirement. Some accounts require $1,000 or $10,000 to earn the advertised rate; if your balance falls below that, the rate drops. A $30,000 deposit usually clears any minimum, but confirm it.
Frequently Asked Questions
Do I have to pay taxes on the interest I earn?
Yes. Interest earned in a savings account is taxable income. The bank will send you a 1099-INT form at the end of the year if you earned $10 or more in interest. You report this on your tax return. At 4.5% APY, $30,000 earns $1,350, which is taxable income in the year you earn it.
Can I lock in a rate so it does not go down?
No. Savings account rates are variable, meaning the bank can change them at any time. A certificate of deposit (CD) locks in a rate for a set period — typically three months to five years — but you cannot withdraw the money early without a penalty. If you want a may provide rate, a CD is the tool, but you lose access to the money.
What if I add money to the account during the year?
You earn interest on whatever balance is in the account each day. If you deposit an additional $10,000 after six months, that $10,000 earns interest for the remaining six months at the same rate. The bank calculates interest daily, so timing matters slightly, but the difference is small.
Is there a difference between APY and APR for savings accounts?
APY (annual percentage yield) includes the effect of compounding; APR (annual percentage rate) does not. For savings accounts, always look at the APY, because that is what you actually earn. APR is used for loans and credit cards, not savings.
Should I split $30,000 across multiple banks to earn more?
No. The FDIC insures up to $250,000 per depositor per bank, so your entire $30,000 is protected at one bank. Splitting it across multiple banks does not increase your earnings — the rate is the same everywhere. The only reason to use multiple banks is if you want to diversify or if one bank has a higher rate for a specific account type.