expense ratio
Financial term for the proportion of costs to revenue, assets, or another base figure. Common in business, accounting, and investment contexts.
The expense ratio of this mutual fund is 0.5% per year.
A high expense ratio puts pressure on profits.
費用対効果 is 'cost-effectiveness', focusing on the balance between cost and benefit, whereas 経費率 is a pure financial ratio.
Compound of 経費 (expenses) and 率 (rate, ratio). A straightforward Sino-Japanese financial term.