tier 1 capital to total risk-weighted assets (Tier1 capital ratio) which, from a regulator’s point of view, is a core measure of a bank’s financial strength (Aebi, 2012)
 
A measure of regulatory capital, equal to the ratio of Tier I capital to average total assets (Belkheir, 2009)
 
 
Tier 1 capital is the core measure of a bank's financial strength from a regulator's point of view. It is composed of core capital, which consists primarily of common stock and disclosed reserves (or retained earnings), but may also include non-redeemable non-cumulative preferred stock. (Wikipedia)