Capital adequacy ratio calculator
Enter your capital and risk-weighted assets to get your CET1, Tier 1, total capital and leverage ratios against the Basel III minimums and buffers.
How the calculation works
| Ratio | Formula | Basel III minimum |
|---|---|---|
| CET1 ratio | CET1 capital ÷ RWA | 4.5% |
| Tier 1 ratio | (CET1 + AT1) ÷ RWA | 6% |
| Total capital ratio | (CET1 + AT1 + Tier 2) ÷ RWA | 8% |
| Leverage ratio | Tier 1 capital ÷ exposure measure | 3% |
On top of the minimums, all banks must hold a capital conservation buffer of 2.5% of RWA in CET1. A countercyclical buffer (0 to 2.5% of RWA, set by national authorities) and, for global systemically important banks, an additional surcharge can apply. The calculator lets you enter these buffers and shows whether your CET1 covers them after meeting the 6% and 8% minimums, because CET1 is used first to meet those minimums.
Frequently asked questions
What is a good capital adequacy ratio?
Under Basel III, banks must hold at least 4.5% CET1, 6% Tier 1 and 8% total capital as a share of risk-weighted assets, plus a 2.5% CET1 capital conservation buffer. Many banks hold well above these levels; your own supervisor sets the exact requirement.
What is included in the capital adequacy ratio?
The numerator is regulatory capital (CET1, Additional Tier 1 and Tier 2) and the denominator is risk-weighted assets. The leverage ratio instead divides Tier 1 capital by a non-risk-based exposure measure.
Is this calculator official?
No. It applies the Basel Committee's published minimums to the numbers you enter. National rules, supervisory add-ons and your bank's own targets can be higher.
Sources: Basel Committee on Banking Supervision, Basel Framework (RBC20 calculation of minimum risk-based capital requirements; LEV20 leverage ratio) and Basel III international regulatory framework for banks, bis.org; BIS FSI summary of the capital conservation and countercyclical buffers. Checked 10 October 2026.