# Casita — Calculadora de Hipotecas
# https://casitacalc.com

> Casita is a free mortgage calculator covering Spain, Mexico, Argentina, Colombia, Chile, and the US Hispanic market. All calculations use the French amortization system. Data from ECB (Euribor), Banxico (TIIE), BCRA (UVA), and CMF Chile (UF) is updated in real-time.

## Calculators
- Monthly payment (French system): /es-ES/
- Amortization schedule: /es-ES/amortizacion
- Affordability (DTI): /es-ES/capacidad
- Purchase costs by region: /es-ES/gastos
- Scenario comparison: /es-ES/comparar
- Early repayment (Ley 5/2019): /es-ES/amortizacion-anticipada
- Euribor tracker: /es-ES/euribor
- ITP by autonomous community: /es-ES/gastos/itp
- UVA inflation projection: /es-AR/simulador-uva
- Infonavit vs Bank: /es-MX/infonavit
- FHA/PITI calculator: /en-US/fha-calculator
- Subrogation (bank switching): /es-ES/subrogacion
- Optimal amortization calendar: /es-ES/amortizacion-optima

## API Endpoints (JSON)
- Live rates: /api/rates/ES (Euribor), /api/rates/MX (TIIE), /api/rates/AR (UVA), /api/rates/CL (UF)
- Content scripts: /api/content/generate

## Guides
- Spain buying guide: /es-ES/guia/hipoteca-espana
- Infonavit 2026 guide: /es-MX/guia/infonavit-2026
- FHA guide for Hispanics: /en-US/guide/fha-loan-calculator

## Coverage
- Spain: 17 autonomous communities + Ceuta + Melilla, ITP rates, Euribor
- Mexico: 10 states, TIIE, Infonavit/Fovissste/Cofinavit, ISAI
- Argentina: 6 provinces, UVA/CER, inflation projections
- Colombia: 6 departments, Decreto 583 (DTI 40%), UVR, Mi Casa Ya
- Chile: 6 regions, UF, dividendo, subsidies DS1/DS49
- USA: 10 states, FHA/VA/conventional, PMI, property taxes

## Formulas Used
- Monthly payment: M = P * [r(1+r)^n] / [(1+r)^n - 1]
- TAE: Newton-Raphson method solving PV equation
- DTI: Monthly payment <= 35% net income (Spain), 40% (Colombia), 25% (Chile), 43% (USA)

## Data Sources
- European Central Bank (ECB): Euribor via SDMX API
- Banco de Mexico (Banxico): TIIE via SIE API
- Banco Central de la Republica Argentina (BCRA): UVA via API v4.0
- Comision para el Mercado Financiero (CMF Chile): UF via mindicador.cl
- datos.gov.co: Colombian mortgage rates via Socrata API