Where your money lives.
Where the story starts You just got a part-time job, and your first paycheck is on the way: $600 for two weeks of work. Right now your only savings is $300 in cash in a shoebox. Your manager hands you a direct deposit form and asks which bank account your pay should go to. You don't have one yet. So where should your money live?
The two basic bank accounts: a checking account for spending and a savings account for money you set aside.
Cash can be lost or stolen and earns nothing. A bank keeps it safe, lets you pay with a card or an app, and pays you to hold your savings.
Your pay lands in checking. Keep enough there for your bills plus a little extra, and move the rest to savings.
Personal bankers help people choose and open accounts. Bank treasury teams decide what interest rate savings accounts pay.
What you're looking at: a sketch, not real data. Your $600 paycheck drops into checking, which comes with a debit card. Money you don't need this month moves over to the savings jar, where it earns interest.
Two accounts, two jobs.
A bank gives you two basic accounts, and each one has its own job. A checking account is for money moving in and out every day. A savings account is for money you're setting aside for later.
- Checking account
- Your $600 paycheck lands here, and your $45 phone bill and a $12 lunch come out of here.
- Savings account
- Money you won't touch this month, like $500 you're building up for a car, waits here.
Savings pays you to wait
A savings account pays you interest for keeping money in it. Banks show the rate as an APY, short for annual percentage yield: the percent your balance earns in one year. Most checking accounts pay little or no interest.
- APY
- 4% APY means each $100 earns about $4 in a year.
- Interest
- $500 left in savings for a year at 4% APY earns about $20. That $20 is the interest.
Rates change over time. In 2025, basic savings accounts at many big banks paid about 0.01%, and many online savings accounts paid about 3.5% to 4%. This lesson uses 4% to keep the math easy.
How money moves between them
Your pay usually reaches checking by direct deposit. You spend from checking with a debit card, and bills can come out on their own on autopay. Between your two accounts you make a transfer, which at the same bank usually happens right away.
- Direct deposit
- Your $600 paycheck shows up in checking on payday, every other Friday.
- Debit card
- You buy a $12 lunch, and $12 leaves checking right away.
- Transfer
- You move $500 from checking to savings in your bank's app.
What you're looking at: a diagram, not data. Green arrows bring money in, red arrows take it out. Your paycheck arrives in checking by direct deposit. Card swipes and autopay bills leave from checking. A transfer moves money you don't need yet over to savings.
Side by side
| Checking | Savings | |
|---|---|---|
| Main job | Everyday spending | Money set aside for later |
| Paycheck lands here | Usually | Rarely |
| Debit card | Yes | Usually no |
| Interest | Little or none | Yes, shown as APY |
| Taking money out | As often as you like | Many banks allow about 6 times a month |
When checking runs dry
If you spend more than you have in checking, that's an overdraft. The bank may cover the gap and charge an overdraft fee. Some big banks charge about $35 each time, some charge less, and some charge nothing. That's why people keep a cushion in checking: extra money on top of the bills, for surprises like a flat tire.
- Overdraft
- You have $40 in checking and swipe your card for $60. You're $20 short. If the bank covers it and charges $35, you now owe the bank $20 + $35 = $55.
- Cushion
- Your bills until payday are $250. Keeping $150 more on top of that is your cushion. In this lesson, aim for a cushion of $100 to $200.
Split your $900
Your $300 in cash plus your $600 paycheck makes $900. Your bills and spending until the next paycheck, two weeks away, come to $250: phone $45, gas $80, groceries $110 and streaming $15. Drag the slider to choose how much goes to savings.
What you're looking at: your checking balance as a blue bar, on a scale from $0 to $900. The red zone is the $250 you'll spend before the next paycheck. The green zone, from $250 to $450, is a $100 to $200 cushion. The savings card shows what the rest earns in a year at 4% APY.
Two minutes. Just listen.
Tap any line to jump to it.
Run your bank app.
This is a practice bank app with your two accounts. You'll run one month, a week at a time. Before each week, move money between checking and savings. Then the week plays out, and bills and card swipes come out of checking. Two goals: never let checking drop below $0, since each overdraft costs a $35 fee, and keep as much as you safely can in savings, where it earns 4% APY.
The logic, step by step.
Every payday, you answer three questions: how much checking needs, how much moves to savings, and what that savings will earn.
Step 1: How much checking needs
Add up everything you'll spend before your next paycheck arrives. Then add your cushion for surprises. That total is what to keep in checking.
- Spending until payday
- Phone $45 + gas $80 + groceries $110 + streaming $15 = $250
- Cushion
- $150, in the middle of the $100 to $200 range
- Keep in checking
- $250 + $150 = $400
Step 2: Move the rest to savings
Whatever is left over after the checking amount goes to savings.
- Move to savings
- $900 − $400 = $500
Step 3: What savings earns
If the balance stays the same all year, the interest for the year is the balance times the APY. To use a percent in math, divide it by 100 first. So 4% becomes 4100 = 0.04. For a rough monthly amount, divide the yearly interest by 12.
- At 4% APY
- $500 × 0.04 = $20 a year, or about $2012 ≈ $1.67 a month.
- At 0.01% APY
- 0.01% is 0.01100 = 0.0001, so $500 × 0.0001 = $0.05 a year. Five cents.
- The difference
- $20 − $0.05 = $19.95 a year, on the same $500, just from picking the account.
Why not keep everything in savings?
Your debit card and your autopay bills pull from checking, not savings. If checking is too low, a bill can overdraw it before you notice. Many banks also allow only about six withdrawals or transfers out of savings each month, and some charge a fee past that. Savings is built for waiting, not for paying.
Why not keep everything in checking?
Checking pays little or no interest, so the extra money there earns nothing. It's also easy to spend by accident: every dollar in checking is one swipe of your debit card away. Money in a separate savings account is a little harder to reach, which helps it stay saved.
Worked example: the next payday
- Payday. Two weeks later, $150 is left in checking, and another $600 paycheck arrives. Checking now has $150 + $600 = $750.
- Spending until the next payday. Car insurance $110 + groceries $60 + gas $40 = $210.
- Keep in checking. $210 + a $150 cushion = $360.
- Move to savings. $750 − $360 = $390.
- What it earns. $390 × 0.04 = about $15.60 a year, added on top of what's already there.
Many banks let you set up an automatic transfer on payday, so this happens without you having to remember it.
Bees keep two kinds of honey.
Inside a hive, the cells near the middle hold honey and pollen that feed the colony every day. Honey for winter goes in the outer cells. Once it's ready, the bees seal each of those cells with a wax cap, and they don't open the caps until they need them. Your checking account is the open cells. Your savings account is the capped ones.
What you're looking at: an illustration, not data. The open yellow cells in the middle hold honey for daily use, and the orange ones hold pollen. The pale cells on the left and right are sealed with wax, storing honey for winter.
Why this sticks. A hive that eats its capped honey in summer starves in winter. A hive with no open honey can't feed itself today. It needs both, kept apart, and so does your money.
The page you'd copy down.
- Checking account: everyday money in and out. Direct deposit, debit card, bills. Little or no interest.
- Savings account: money set aside for later. Earns interest. Many banks allow about 6 withdrawals a month.
- APY: the percent your balance earns in a year. Interest for a year = balance × APY, with the APY as a decimal (4% = 0.04).
- Keep in checking = spending until next payday + a cushion. Move the rest to savings.
- Overdraft: spending more than checking holds. The bank may charge a fee, about $35 at some big banks.
Fill in the blanks
Grab a friend or a study group.
Rate race
Each person picks a different bank or credit union and looks up its savings APY on its website. Work out what $1,000 would earn in a year at each one. Whose pick wins, and by how much?
Read the fine print
Pick one bank's checking account page together. Find the monthly fee, how to avoid it, and the overdraft fee. Would this account work for someone with a $600 paycheck?
Sixty-second split
One person names a paycheck and a list of bills. The other has 60 seconds to say how much stays in checking and how much moves to savings, with the math out loud. Then switch.
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, Ana, keeps $4,000 in checking and nothing in savings. Her checking pays no interest. She's paid twice a month, and she spends about $750 between paychecks.
Your task: recommend how much Ana should keep in checking and how much she should move to savings. Then tell her how much the savings part would earn in a year at 4% APY.
See a model answer
Keep in checking: $750 of spending until her next paycheck + a cushion of about $250 = $1,000. (A bigger cushion fits her bigger budget.)
Move to savings: $4,000 − $1,000 = $3,000. At 4% APY, that earns $3,000 × 0.04 = $120 a year, compared with $0 in checking.
Tell Ana: her bills and card still run from checking, and she can transfer money back from savings any time she needs it.
Every money move starts here.
What you're looking at: a map of where this lesson fits in the course. Read it left to right: what comes before, this lesson in the middle, and the later lessons that build on it.
- BeforeStart of the course
- You are hereChecking and savings
- Next · Unit 1Open your first account
- Later · Unit 3Budgeting
- Later · Unit 3High-yield savings
- Later · Unit 5Why invest at all?