CUs under $50M average a 70.42% efficiency ratio. CUs over $10B average 42.72% — a 28-point spread. Almost all of the improvement happens in the first three tiers; beyond $1B the curve flattens.
All 4,373 federally insured US credit unions, grouped into five asset tiers from under $50M to over $10B. Average efficiency ratio and ROA per tier, latest quarter.
| Asset tier | Avg (asset tier) | Range | Credit unions | Avg efficiency ratio (lower = better) |
|---|---|---|---|---|
| Under $50M | Under $50M | 1,971 | 70.42% | |
| $50M – $250M | $50M – $250M | 1,262 | 61.97% | |
| $250M – $1B | $250M – $1B | 673 | 58.44% | |
| $1B – $10B | $1B – $10B | 446 | 51.00% | |
| Over $10B | Over $10B | 21 | 42.72% |
Scale economics in CUs are real and large. A CU under $50M spends about 70¢ of every revenue dollar on operations; a CU over $10B spends about 43¢. That 28-point gap is the single biggest structural advantage large CUs have over small ones, and it's bigger than any growth-rate gap you'll find.
The curve isn't linear. Most of the improvement happens in the transitions $50M → $250M and $250M → $1B. Between $1B and $10B+, efficiency only improves by a few more points. So if you're a $300M CU, getting to $1B materially changes your unit economics. Getting from $1B to $5B doesn't.
This is the math driving CU consolidation. Two $200M CUs merging to a $400M CU sits in a meaningfully more efficient tier than either parent. The decision is rarely about cost-cutting at the existing CU and almost always about which tier of the curve the combined entity lands on.
Tudovu Research is published from NCUA call-report data via CU Growth Plan. New analysis each quarter as fresh data lands.
Tudovu's Industry Data Explorer runs this same analysis on a custom peer set — pick the asset tier, state, charter type, or specific competitors and we'll show you where your CU sits in the curve.