Net interest spread: Net interest spread is the gap between the rate a bank earns on its assets and the rate it pays on its funding.
How it is calculated
Yield on earning assets less cost of funds. Unlike net interest margin it gives the bank no credit for funding part of its balance sheet with money that costs nothing.
Formula
Net interest spread = yield on earning assets - cost of funds
What banks reported in Q2 2026
Across every bank that filed for Q2 2026, the median net interest spread was 3.23%, with the middle half between 2.75% and 3.72%. The right comparison is almost always the row for the bank’s own size rather than the industry line.
| Bank size (total assets) | Bottom quartile | Median | Top quartile |
|---|---|---|---|
| Under $100M | 2.73% | 3.34% | 3.89% |
| $100M - $300M | 2.83% | 3.34% | 3.84% |
| $300M - $1B | 2.83% | 3.28% | 3.70% |
| $1B - $3B | 2.65% | 3.07% | 3.49% |
| $3B - $10B | 2.51% | 2.99% | 3.44% |
| $10B - $100B | 2.40% | 2.96% | 3.30% |
| Over $100B | 1.55% | 2.42% | 3.08% |
Source: BankingLens, computed from FFIEC call reports for the quarter ending June 30, 2026. Quartiles are calculated across the full population of filing banks in each size band, not sampled. Non-insured non-deposit trust companies are left out of every statistic: they take no deposits and make no loans, so a margin or a funding cost computed for them has no meaning.
How to read it
Spread is the pricing result. Margin is the pricing result plus the free funding. The distance between the two numbers at a given bank is roughly what its noninterest bearing deposits and its capital are worth to it each year.
The common mistake. Using spread and margin interchangeably. Two banks can run an identical spread and differ by a full point of margin, entirely because one of them funds a fifth of its book for nothing.
Go deeper
- What is a good net interest margin for a bank?
- What is a good cost of funds for a bank?
- BankingLens pricing and what a subscription adds: percentile rank against the bank’s own FFIEC peer group, fourteen quarters of trend, and the flags an examiner reaches for first.
See also. Net interest margin, Yield on earning assets, Cost of funds, Noninterest-bearing deposits.
Every figure on this page is computed from FFIEC call reports for the quarter ending June 30, 2026 and is not modeled, estimated or sampled. This page is generated by _tools/seo/build_glossary.mjs and carries no figure that was typed in. See our methodology and disclaimer. Definitions are general guidance, not regulatory or investment advice.