Pull up your last three bank statements and find the single lowest balance in each month. Not the average. The low point, usually the day before payday. Whatever that number is, a chunk of it hasn’t moved in months, and it’s earning you roughly nothing. If you’ve ever googled how much money to keep in checking, you got told “one month of expenses plus a cushion.” For most people paid every two weeks, that rule is too generous, and the extra is costing something like $150 a year.
I’m not going to argue you should run your checking account to zero. Bounced payments are expensive and stressful. My claim is narrower: the right amount is set by your lowest balance and the timing of your bills, not by your monthly spending total, and the gap between those two numbers is money you can move this weekend.
The one-month rule ignores your second paycheck
Citi and Capital One both publish versions of the standard advice. Citi says to cover a month of expenses plus a buffer of $100 to $500. Capital One says to add up bills, everyday spending, and a slice of your annual costs, then keep a buffer of at least $100. Neither is wrong, exactly. Both just assume all of next month’s spending has to be sitting in the account at once.
It doesn’t, if you’re paid every other Friday. Your rent goes out on the 1st, but your groceries on the 22nd are paid for by the check that landed on the 15th. A month of expenses on hand at all times means you’re holding about half a month of money that the next paycheck was always going to cover.
You can see this play out in real data. The JPMorgan Chase Institute tracked checking balances for millions of Chase customers and found that before the pandemic, typical households held about two to four weeks of spending in their accounts (roughly 13 days for the lowest-income quarter and 26 days for the highest), according to its July 2023 report on cash buffers. Most people already live on less than a month of float. In my experience, the people holding more aren’t any safer for it. They just haven’t looked.
Your low point shows the money that never moves
Your monthly expense total is a guess. Your low point is a measurement. It already reflects your actual paydays, your rent date, your car payment, the subscription that renews on the 9th. Every bill you have has already hit by the time you reach that number.
So here’s the audit. Open your three most recent statements (most banks show a daily balance graph in the app, which is faster). Write down the lowest balance in each month. Take the smallest of the three. That’s your floor, the money that survived three straight months of you living your life.
Then decide what part of that floor you actually want as a safety margin. I use one week of spending. Divide your monthly spending by 4.3 and round up. If a bank fee waiver depends on a minimum balance, use that number if it’s higher: Chase Total Checking charges $15 a month unless you get $500 in electronic deposits or keep a $1,500 minimum daily balance, according to CompareAccounts’ fee listing. If you have direct deposit, the balance requirement doesn’t apply to you, and your buffer can stay small.
Everything between your floor and your buffer is idle. Move it.
The idle money is worth about $160 a year
Here’s how that works with real numbers. Say you spend about $4,200 a month and get paid every other Friday. Your three monthly low points were $5,100, $5,800, and $4,900. Your floor is $4,900.
One week of spending is $4,200 divided by 4.3, which is about $977. Call your buffer $1,000. You have direct deposit, so no minimum balance fee is in play.
That leaves $3,900 sitting in checking that you never touched over three months. The FDIC’s national rate for interest checking was 0.07% in October 2026 (FRED lists the rate cap at 0.82%, which is the national rate plus 0.75 points). At 0.07%, $3,900 earns $2.73 a year. If your account pays no interest at all, which is common at big banks, it earns zero.
Meanwhile, competitive online savings accounts were paying about 4.20% APY in early November. $3,900 at 4.20% earns $163.80 in a year. The difference is about $161, for moving money you have already proven you don’t need in checking. Even the FDIC’s national average savings rate, 0.38% in October, would beat checking by a few dollars, but the real money is at the online banks.
Not life-changing, I know. It’s also free money for a ten-minute transfer, and it compounds every year you leave it there.
The typical family’s cash is parked where it earns nothing
The Federal Reserve’s 2025 Survey of Consumer Finances, released October 9, put the median family’s transaction account balance at $8,200, down 6% from 2022. That figure lumps checking, savings, and money market accounts together, so it doesn’t tell you how much is earning interest. But it does tell you the typical family has a meaningful pile of cash, and the question is mostly where it lives.
Keeping cash in checking feels safer because you can see it every time you open your banking app. That visibility is the whole problem. Money you can see gets spent, and money that isn’t spent drifts upward until it’s a few thousand dollars of nothing. A savings account linked to your checking keeps it one transfer away, which is close enough for anything except a same-day emergency, and that’s what the one-week buffer is for.
If you want this to happen without you, split your direct deposit so a fixed amount goes straight to savings every payday. We walked through the setup in our guide to split direct deposit. Set the savings slice equal to whatever you moved during the audit, divided across your paychecks, and the float stops building back up.
November and December need a temporary floor, not a permanent one
This is the one time of year I’d raise the number, briefly. Holiday spending is lumpy. Gifts, travel, and hosting land in a five-week window, and the day your balance bottoms out can shift by a week when a big gift order and a flight land on the same card payment.
The JPMorgan Chase Institute’s 2019 “Weathering Volatility 2.0” study found that families hit a spending spike about once every four months, and that income spikes (bonuses, extra paychecks) were most common in March and December. So December can cut both ways for your account: the outflow is bigger, and sometimes so is the inflow.
My approach: keep your holiday budget in savings and move it to checking in weekly chunks, rather than parking the full amount in checking on November 1. If you’d rather keep it simple, raise your buffer by your total holiday budget through December 31, then rerun the low-point audit in the second week of January. Any year-end bonus that lands in checking goes straight to savings the day it posts. Don’t let it sit through January.
One more thing for January: if you moved money to an account with a promotional rate, check when that promo ends. Some of them drop sharply after 90 days. We covered what to do when that happens in our piece on expiring promo APYs.
How much money to keep in checking comes down to a 10-minute audit
So, how much money to keep in checking? Enough to clear your lowest point of the month with a week of spending to spare, plus whatever your bank requires to waive its fee. For most people paid biweekly, that’s well under a month of expenses.
This week, pull three statements, find your floor, subtract a one-week buffer, and move the difference. Put a reminder on your calendar for the second week of January to do it again after the holidays. If your floor was $4,900 like the example above, that’s about $160 a year you were leaving with the bank. If it was higher, you’re leaving more.
