Same $3,600. $144 a year, or $0.36?
The story so far Your emergency fund is full: $3,600 in your Riverbend savings, which pays 4.00% APY. Your cousin Ana also saved $3,600, but she keeps hers in savings at the big bank where she has checking, which pays 0.01% APY. In one year your money earns $144. Hers earns 36 cents. Same amount, same safety, very different result. This lesson shows why, and how to pick a savings account that pays you well.
A high-yield savings account is a savings account that pays far more interest than the usual one, often from an online bank.
Your emergency fund should sit safely, but it doesn't have to sit still. A better rate pays you every month for doing nothing.
Compare APYs, check that the account is FDIC or NCUA insured, read the fees and the fine print, then link it to your checking.
Personal bankers open accounts. Treasury and pricing analysts at banks set the rates. Bank examiners at the FDIC check that banks are safe.
What you're looking at: a sketch of two savings accounts holding the same $3,600. The coins beside each are the interest it pays in a year: one coin at 0.01%, a tall stack at 4.00%.
Why some savings pay 400 times more.
Every savings account at an insured bank is equally safe. What changes is how much the bank pays you. Here's how to read the rate, why it varies so much, and what to check before you switch.
Reading the rate: APY
You met APY in Unit 1: it's the share of your balance that you earn in one year. Banks pay interest every month, and each month's interest starts earning interest too. That's called compounding. The APY already counts it, so it's the fair number to compare. The plain interest rate is a little lower.
- One year at 4.00% APY
- $3,600 × 0.04 = $144.
- First month
- About $14412 = $12, and the month after earns on $3,612.
- Interest rate
- A 3.93% interest rate paid monthly works out to a 4.00% APY. Always compare APY to APY.
What most savings accounts pay
The FDIC tracks the average savings rate across U.S. banks. In October 2026 it was 0.38%. Many of the biggest banks pay just 0.01%, because most customers never move their money. A high-yield savings account pays many times the average. Online banks can do that because they don't pay for branches, so they pass the savings to you.
- Ana, 0.01%
- $3,600 × 0.0001 = $0.36 a year.
- Average, 0.38%
- $3,600 × 0.0038 = $13.68 a year.
- You, 4.00%
- $3,600 × 0.04 = $144 a year: $144 − $13.68 = $130.32 more than average.
What you're looking at: how much interest one balance earns at three rates, with no deposits or withdrawals. 0.01% is a typical big-bank rate, 0.38% is the FDIC national average (October 2026), and the green bar is the APY you pick. Bar length is interest earned. Real rates change over time.
Is it safe? Check the insurance
A high rate is only worth it if your money is protected. At a bank, look for FDIC insurance; at a credit union, look for NCUA insurance. Both protect up to $250,000 per person, per bank. Some apps advertise high rates but aren't banks themselves; check that the money is held at an insured bank in your name.
- Your $3,600
- Riverbend is FDIC-insured, and $3,600 is far below $250,000, so all of it is protected, just like Ana's.
The fine print: three things to check
1. The rate can change. Savings rates are variable: they usually rise and fall with the Federal Reserve's rate, which you'll meet in Unit 9. 2. Teaser rates. Some banks show a high rate that only lasts a few months. 3. Fees and minimums. A monthly fee can wipe out the interest.
- Teaser
- 5.00% for 3 months, then 0.50%: 3 months earns $3,600 × 0.05 × 312 = $45, and 9 months earns $3,600 × 0.005 × 912 = $13.50. Total $58.50, less than the steady 4% account's $144.
- Fee
- 4.00% with a $5 monthly fee: $144 − 12 × $5 = $84.
Moving money, and tax on interest
If your savings is at a different bank than your checking, moving money between them usually takes 1 to 3 business days. For an emergency fund that's fine, but keep a small cushion in checking for same-day surprises. And remember Lesson 2.3: interest is income. The bank sends a 1099-INT, and it's taxed at your marginal rate from Lesson 2.2.
- Tax
- In the 12% bracket: $144 × 0.12 = $17.28 of tax. You keep $144 − $17.28 = $126.72, still far more than $0.36.
Two minutes. Just listen.
Tap any line to jump to it.
Pick the better account.
You have $3,600 to keep in savings for a year. Six times, two banks make you an offer. Read both cards and tap the one you'd choose. One try each.
What you're looking at: made-up account offers, each for $3,600 kept one year. Interest is figured with APY: balance × APY.
The logic, step by step.
Five calculations compare any two savings accounts.
Step 1: One year of interest
- 4.00%
- $3,600 × 0.04 = $144.
Step 2: The difference
- 4.00% vs. 0.38%
- $3,600 × (0.04 − 0.0038) = $3,600 × 0.0362 = $130.32.
Step 3: Subtract fees
- $5 fee
- $144 − $60 = $84.
Step 4: After tax
- 12% bracket
- $144 × 0.88 = $126.72.
Step 5: Several years
- 5 years at 4%
- $3,600 × 1.045 = $3,600 × 1.2167 = $4,379.95, so $779.95 of interest. At 0.38%: $3,600 × 1.00385 = $3,668.92, only $68.92.
Worked example: a bigger balance
- The setup. Rosa, the car seller from the last lesson, keeps her $9,000 emergency fund at a bank paying 0.38%.
- Now. $9,000 × 0.0038 = $34.20 a year.
- High-yield. At 4.00%: $9,000 × 0.04 = $360 a year.
- Extra. $360 − $34.20 = $325.80 more every year.
- Per month. $325.8012 = about $27.15 a month, for one afternoon of opening an account.
Two seeds, sun or shade.
Plant two seeds of the same kind in the same soil, with the same water. Put one in full sun and one in deep shade. Plants make their food from sunlight, so the one in the sun grows far faster, even though nothing else is different.
What you're looking at: an illustration, not data. Two pots with the same soil and the same kind of seed; only the light is different.
Why this sticks. Your $3,600 is the seed, and it's equally safe in either spot. The rate is the sunlight. Moving the same money into the sun is the easiest growth you'll ever get: no extra risk, no extra work.
The page you'd copy down.
- APY = what you earn in a year, with compounding (interest on interest) counted. Compare APY to APY. The plain interest rate is a bit lower.
- National average savings rate: 0.38% (FDIC, Oct 2026). Many big banks: 0.01%. High-yield: many times more, often at online banks with no branches.
- One year: balance × APY. $3,600 × 4% = $144 vs. $13.68 at 0.38%.
- Safety: FDIC (banks) or NCUA (credit unions), up to $250,000 per person, per bank.
- Check the fine print: rates are variable, watch for teaser rates, and fees can erase the interest.
- Transfers to another bank take 1 to 3 business days; keep a small cushion in checking.
- Interest is taxable income (1099-INT), at your marginal rate. 12% bracket: $144 → keep $126.72.
Fill in the blanks
Grab a friend or a study group.
Rate hunt
Everyone looks up the savings APY at their own bank, or a parent's. Line them up from lowest to highest. How much would $3,600 earn at each?
Spot the catch
One person writes a savings offer with a hidden catch, like a teaser rate or a fee. The others find it and figure out what $3,600 really earns.
Sun or shade?
Ask a family member where their savings lives and what it pays. Use the calculator together to show what moving it would earn in five years.
Just you and your money.
These stay on this device. Nobody else sees them.
Exam-style questions.
Written the way a college exam would ask them. Each right answer on the first try is worth 10 xp.
On the job: you're the personal banker
A customer, Maria, comes to your desk at an online bank. Here's her situation:
- She has $8,000 of savings at a big bank.
- That savings account pays 0.01% APY.
- Your bank's high-yield savings pays 4.00% APY, with no fees and FDIC insurance.
- She's worried that a high rate means her money is less safe.
Your task: tell Maria how much she earns now in a year, how much she'd earn with you, and answer her worry about safety.
See a model answer
What she earns now: $8,000 × 0.0001 = $0.80 a year.
With you: $8,000 × 0.04 = $320 a year, or $319.20 more. That's about $26.60 a month.
Safety: both banks are FDIC-insured, and $8,000 is far below the $250,000 limit, so her money is equally protected at either one. The rate is higher because an online bank has no branches to pay for, not because it's riskier. Two things to know: the rate is variable, so it can go down if the Fed cuts rates, and moving money to her checking takes 1 to 3 business days.
From a safe fund to a growing one.
What you're looking at: a map of where this lesson fits in the course. Read it left to right: the lesson that comes before, this lesson in the middle, and the lessons it connects to.
- Before · Unit 3Build an emergency fund
- You are hereMake your savings earn more
- Next open · Unit 5Why invest?
- Later · Unit 9Interest rates and the Fed
- Back · Unit 2File your tax return