# The Math Says

> A calculator hub for big financial decisions. Every calculator gives you a clear verdict (green light, depends, or don't do it), not just a number, because the number is the easy part and deciding what to do with it is the hard part.

The Math Says helps consumers, homeowners, and car buyers run transparent, mathematically grounded evaluations before committing to mortgages, refinances, equity loans, or auto decisions.

## Core Calculators

- [Mortgage Refinance Break-Even Calculator](https://themathsays.com/calculators/mortgage-refinance-break-even-calculator/): Calculates the exact months needed to recover upfront closing costs when refinancing a home mortgage.
- [30 to 15 Year Refinance Calculator](https://themathsays.com/calculators/30-to-15-year-refinance-calculator/): Evaluates whether refinancing into a 15-year mortgage saves interest and makes cash flow sense.
- [ARM vs Fixed Mortgage Calculator](https://themathsays.com/calculators/arm-vs-fixed-mortgage-calculator/): Compares adjustable-rate mortgages with traditional fixed-rate loans under rate adjustment scenarios.
- [Pay Off Mortgage vs Invest Calculator](https://themathsays.com/calculators/pay-off-mortgage-vs-invest-calculator/): Mathematical comparison of extra principal mortgage payments versus investing in the stock market.
- [Biweekly Mortgage Payment Calculator](https://themathsays.com/calculators/biweekly-mortgage-payment-calculator/): Calculates interest saved and years shaved by making 26 half-payments per year.
- [Refinance to Remove PMI Calculator](https://themathsays.com/calculators/refinance-to-remove-pmi-calculator/): Tests if rising home value or refinancing removes private mortgage insurance early.
- [HELOC vs Cash-Out Refinance Calculator](https://themathsays.com/calculators/heloc-vs-cash-out-refinance-calculator/): Compares a second-lien home equity line of credit with refinancing an entire first mortgage.
- [Home Equity Loan vs Cash-Out Calculator](https://themathsays.com/calculators/home-equity-loan-vs-cash-out-calculator/): Analyzes fixed second-mortgage home equity loans against cash-out refinancing.
- [FHA to Conventional Refinance Calculator](https://themathsays.com/calculators/fha-to-conventional-refinance-calculator/): Analyzes removing lifetime FHA mortgage insurance premiums (MIP) by switching to conventional.
- [Lease vs Buy Car Calculator](https://themathsays.com/calculators/lease-vs-buy-car-calculator/): Total cost of ownership comparison between auto leasing and vehicle financing.
- [Auto Loan Refinance Calculator](https://themathsays.com/calculators/auto-loan-refinance-calculator/): Evaluates interest savings and monthly payment reduction from refinancing a vehicle loan.
- [Insurance Deductible Optimizer](https://themathsays.com/calculators/insurance-deductible-optimizer/): Determines the optimal auto or home insurance deductible based on claim frequency math.

## Supporting Resources

- [Methodology](https://themathsays.com/methodology/): Complete mathematical formulas, amortization equations, and financial decision criteria.
- [About](https://themathsays.com/about/): Background on The Math Says editorial independence and transparency.
- [Disclaimer](https://themathsays.com/disclaimer/): Financial calculation notices and non-advisory disclosures.

## Machine-Readable Endpoints

- API Catalog: https://themathsays.com/.well-known/api-catalog (RFC 9727 linkset)
- OpenAPI Specification: https://themathsays.com/openapi.json (OpenAPI 3.1.0)