---
title: "DTI Ratio Calculator"
method: POST
path: "/v1/tools/compute_dti_ratios"
tags: ["TODO_TAGS_REVIEW", "TODO_AP2_EXPORT_REVIEW"]
---

# DTI Ratio Calculator

`POST /v1/tools/compute_dti_ratios`

## Request

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

Front-end (housing) and back-end (total) debt-to-income ratios per Fannie Mae Selling Guide B3-6-02 and Freddie Mac Single-Family Seller/Servicer Guide 5401.2. Classifies the back-end ratio into a standard-manual / extended-manual-compensating-factors / DU-LPA-only / exceeds-max tier and flags whether the loan is within the max DTI for the selected underwriting type (DU, LPA, or manual). Feeds art-222-agency-eligibility-matrix as one of its DTI inputs. Not check_agency_eligibility_matrix itself, which performs the full multi-check eligibility decision.

**Tool URL:** https://ainumbers.co/chaingraph/art-335-compute-dti-ratios.html

## Request body

- object
  - `gross_monthly_income` number
  - `housing_payment_pitia` number
  - `other_monthly_debts` number
  - `underwriting_type` unknown, required

## Response `200`

Successful tool execution result

- object
  - `back_end_dti_pct` integer
  - `dti_tier` string
  - `front_end_dti_pct` number
  - `gross_monthly_income` integer
  - `housing_payment_pitia` integer
  - `max_dti_pct` integer
  - `note` string
  - `other_monthly_debts` integer
  - `regulatory_basis` string
  - `total_monthly_debt` integer
  - `underwriting_type` string
  - `within_max` boolean

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)