How Banks Earn on the Gap Between Savings and Loan Rates

A savings account pays one rate. A loan from the same bank charges a higher one. It is a familiar pattern, and it leads to a natural question: how do banks actually earn money from what looks like a simple exchange, and does understanding it help a household with its own choices? In short, the gap between what a bank pays for money and what it charges for it is a main source of its income, and the same comparison can be run on a household's own savings and debts.

Key takeaways

• A bank earns interest on its loans and investments and pays interest on deposits and other borrowing, and the difference is a main source of income for most banks.
• The Federal Deposit Insurance Corporation tracks this gap as net interest margin, which it reported at 3.32 percent for the banking industry in the second quarter of 2026.
• A simple example with an 8 percent loan and a 2 percent deposit shows a 6 point gap on paper, but the industry-wide margin is smaller because it covers all earning assets.
• A household can run the same comparison on its own balance sheet by looking at what its savings earn and what its debts cost.
• Banks also face costs and risks such as operating expenses and borrowers who do not repay, so the gap is not all profit.

The basic idea

The Federal Deposit Insurance Corporation (FDIC) describes a measure called net interest margin as the difference between the interest income generated by bank lending and investment and the interest expense incurred from bank borrowing, normalized by average earning assets. It adds that for the vast majority of banks, net interest income is the primary source of income.

Put simply, the bank earns interest on loans and investments, pays interest on deposits and other borrowing, and keeps the difference. The FDIC reports the industry-wide figure each quarter. For the second quarter of 2026 it was 3.32 percent, up 1 basis point from the prior quarter. That figure changes with time and conditions.

A simple example

Imagine a hypothetical bank that holds an $80,000 certificate of deposit paying the saver 2 percent. It earns $1,600 a year in interest for the depositor. It also makes an $80,000 loan at 8 percent, which earns $6,400 a year. The gap is $4,800, or 6 percentage points.

This is a teaching example, not a typical bank. The industry-wide margin is much smaller than 6 points because it averages across everything a bank holds, including securities and funds that earn little, and it is measured against all earning assets. The gap is also revenue, not profit. Banks have staff, buildings and technology to pay for, and some borrowers do not repay.

Why rates differ

Loans generally carry higher rates than deposits for several reasons. A lender takes on the chance of not being repaid, the money is tied up for a period of time, and the lender has costs of its own. A depositor, by contrast, usually has access to the money with little or no risk to principal, up to deposit insurance limits. These are general explanations and not a rule for any particular product.

The FDIC also notes that the effect of changing interest rates on a bank's margin is not simple. When rates rise, a bank may have to pay more on some deposits and borrowings, while some of its assets keep earning their older contractual rates. The result can differ from bank to bank.

Running the same comparison at home

The idea is useful because a household can do it on its own balance sheet. Take a hypothetical household with $10,000 in a savings account earning 1 percent and $10,000 of debt costing 8 percent. In a year, the savings earn about $100 and the debt costs about $800, so holding both costs roughly $700 a year in net interest.

That does not mean the savings are a mistake. Cash provides a cushion for surprises, and many households keep one on purpose. The comparison simply shows the price of keeping it, and it can inform how much cash is enough, and whether a different account would pay more. The numbers here ignore taxes, fees and other circumstances.

Questions a household can ask

1. What rate does each of my savings accounts and deposits actually earn?
2. What rate does each debt cost me, and which are highest?
3. How much cash do I want available for emergencies before I weigh paying down a loan?
4. Are there fees that reduce what my accounts earn?
5. When rates change, which of my accounts and loans will adjust, and which will stay fixed?

The takeaway

A bank earning the gap between its borrowing costs and lending income is a business model, not a trick. Seeing it clearly can make a household's own numbers easier to read. The rate paid, the rate earned, and the cash cushion in between are the three things worth seeing side by side.

Common questions

How do banks make money from deposits and loans?

In simple terms, they earn interest on loans and investments and pay interest on deposits and other borrowing. The Federal Deposit Insurance Corporation describes net interest margin as the difference between the interest income from lending and investment and the interest expense, divided by average earning assets.

Is the gap between savings and loan rates the bank's profit?

Not entirely. The gap is revenue before costs such as operating expenses and losses from loans that go unpaid, so the actual profit is smaller.

Can a household use the same idea?

Yes, as a way to look at its own numbers. Comparing the rate on savings with the rate on debt shows what holding both costs each year, though savings also provide a cash cushion that has its own value.

NIFE provides general financial education. LendsightAI and Debt Done Date are separate for-profit partners; optional services may have a fee.