The standard advice is blunt: never sit on cash earning 4.50% while you owe 7.4% on a car loan. Pay the debt, because the loan costs more than the savings earn.
That advice is correct. It is also worth about $139 — and $139 is a thin reason to empty an emergency fund.
The gap between "which option wins" and "by how much" is where most of these decisions actually get made, and almost nobody runs the second number. So let's run it, on one household's real balances.
Where rates stand right now
The Federal Reserve cut three times to close out 2025 and has held the target range at 3.50%–3.75% through the first half of 2026. Savings rates followed it down, but not all the way: the top high-yield savings accounts were still paying up to 4.50% APY as of August 27, 2026, per Fortune's rate tracker, with most online banks clustered between 2.50% and 3.75%.
Two things matter about that 4.50%. First, it's the best offer, not the typical one — the national average on a 12-month CD was 1.68% in July 2026. Second, it's pre-tax. Interest from savings and CDs is ordinary income. At a 22% federal bracket plus a modest state tax, 4.50% becomes roughly 3.4% in your pocket.
That's the number to compare debt against. Not 4.50%.
The household
Priya and Dev have $14,000 in a savings account, and two debts:
- A car loan: $12,500 remaining at 7.4%, 38 payments left
- A credit card: $3,200 at 24.99%
They spend about $3,800 a month. They want to know whether to wipe out the car loan.
The car loan, run start to finish
Put the balance into the loan calculator at 0.6167% per month — that's 7.4% annual divided by 12 — over 38 installments:
The payment is $370.00. Over the 38 remaining months they'll hand the lender $14,060 — meaning $1,560 of interest is still ahead of them. Paying the loan off today erases that $1,560.
Now the other side. Leave the same $12,500 in a 4.50% account for those 38 months and it grows to about $14,370: a gain of $1,870 before tax. After 24% in combined tax, roughly $1,421.
$1,560 saved versus $1,421 earned. Paying off the loan wins by $139 — about $3.66 a month.
The credit card isn't close
Run the same comparison on the $3,200 card balance and the answer stops being subtle. At 24.99%, that balance costs roughly $800 a year to carry. The same $3,200 in savings earns $144 before tax, $109 after.
There is no scenario, no liquidity argument, no tax angle that makes carrying a 24.99% balance alongside idle cash a good idea. If your debt rate starts with a 2, the decision is already made.
What the $139 is actually buying
Once you see that the car loan comparison is nearly a coin flip, the question changes. You're no longer asking which option earns more. You're asking what you'd pay for liquidity — and the answer here is $3.66 a month.
Priya and Dev spend $3,800 monthly, so three months of expenses is $11,400. They have $14,000. If they clear the $12,500 car loan, they're left with $1,500 and a $370 payment gone from the budget — but no buffer at all. A transmission, a layoff, or a deductible puts them straight onto the 24.99% card, where they'd wipe out three years of interest savings in about two months of carrying a balance.
So the sequence writes itself:
- Pay the $3,200 card in full. That's an unambiguous 24.99% return.
- Keep the remaining $10,800 liquid and keep making the $370 car payment.
- Rebuild toward $11,400, then revisit the car loan with whatever is above that line.
Note what didn't happen: they didn't follow the rule that was technically right. The rule was right by $139, and their emergency fund is worth more than $139.
The line where the answer flips
Your own version of this decision comes down to one comparison: your after-tax savings yield against your debt rate.
At a 3.4% after-tax yield, any debt above roughly 3.5% is worth paying down once your emergency fund is intact. Below it — a 2.9% mortgage from 2021, a 0% promotional balance you'll clear before it expires — keep the cash and keep paying on schedule.
Two warnings on that second category. Promotional 0% offers now run about 13 months on average, and the deferred-interest versions bill you retroactively for the entire period if any balance remains on day one of month 14. And "0% financing" from a dealer or retailer often isn't; if you're offered a discount for paying cash instead, the difference is the interest, and the interest rate calculator will back out the real rate from the payment and term.
If you're weighing this against a mortgage instead of a car loan, the arithmetic runs the same way but the numbers are much larger — we walked through several versions of it in 5 mortgage payoff myths. And if you want to see what the money does if you leave it invested rather than parked, the compound interest calculator covers the long horizon.
The rule of thumb holds. Just check its margin before you act on it.
Rates cited are from late August 2026 — Fed target range, Fortune's savings and CD surveys, and July 2026 national averages — and change frequently. Tax treatment varies by bracket and state. This is general information, not financial advice.