This ratio is designed to measure the ability of the insurer to absorb above-average losses and the insurer’s financial strength. The ratio is computed by dividing net premiums written by surplus. An insurance company’s surplus is the amount by which assets exceed liabilities. The ratio is computed by dividing net premiums written by surplus. The lower the ratio, the greater the company’s financial strength. State regulators across USA have established a premium-to-surplus ratio of no higher than 3-to-1 as a guideline.