---
title: "Basel III Endgame (US) Capital Impact Estimator"
method: POST
path: "/v1/tools/basel_iii_endgame_capital_estimator"
tags: ["Basel III Endgame", "US capital rules", "expanded risk-based approach", "ERA", "standardised approach", "operational risk", "credit risk", "RWA", "Fed", "OCC", "FDIC", "March 2026 proposal"]
---

# Basel III Endgame (US) Capital Impact Estimator

`POST /v1/tools/basel_iii_endgame_capital_estimator`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/basel_iii_endgame_capital_estimator`
- Auth: none declared

Estimates the risk-weighted asset (RWA) impact on a US bank under the March 19, 2026 federal banking agency NPR implementing Basel III Endgame reforms (consultation closed June 18, 2026). Models the Expanded Risk-Based Approach (ERA) credit risk standardized weights, operational risk Business Indicator Component (BIC), and off-balance sheet conversion factors. Does not include market risk (covered by T340 FRTB tool). Outputs AP2 mandate.

**Tool URL:** https://ainumbers.co/tools/341-basel-iii-endgame-capital-impact-estimator.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `total_assets_bn` number, required: Total assets in USD billions
  - `cet1_ratio_pct` number, required: Current CET1 ratio (%)
  - `gross_income_m` number: 3yr average gross income in USD millions
  - `airb_usage` string: yes | no

## Response `200`

Successful tool execution result

- object
  - `era_rwa_bn` number: Estimated total RWA under ERA in USD billions
  - `rwa_change_bn` number: Change in RWA vs current approach in USD billions
  - `rwa_change_pct` number: Percentage change in RWA
  - `cet1_era_pct` number: Estimated CET1 ratio under ERA
  - `cet1_impact_pct` number: CET1 ratio change in percentage points
  - `distance_to_requirement_pct` number: Distance from ERA CET1 to minimum + conservation buffer + GSIB surcharge
  - `op_risk_rwa_bn` number: Operational risk RWA under BIC in USD billions
  - `impact_label` string: HIGH IMPACT | MODERATE IMPACT | LOWER IMPACT

---

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