CLEAR BY DESIGN
Methods & disclosures
Payment and amortization
For principal P, monthly rate r and n payments, the scheduled principal-and-interest payment is P × r ÷ (1 − (1+r)−n). At zero interest it is P ÷ n. Interest is modeled monthly on the outstanding balance. Extra principal shortens the term; the final payment is capped at the balance plus that month’s interest.
Ownership costs and assumptions
Property taxes and home insurance are entered as annual dollars, HOA dues as monthly dollars, and PMI as an annual percentage of original principal. PMI remains constant throughout the model; automatic termination, requested cancellation and program-specific premiums are not inferred. Taxes, premiums and dues remain constant. Utilities, maintenance, special assessments and tax benefits are excluded.
Other tools
Affordability uses the user’s debt-to-income budget less entered debt and ownership expenses. Refinance and quote tools use simple undiscounted break-even. Quote break-even requires equal loan balances and terms. The rent/buy model compares constant cash costs with manually supplied cumulative principal and value change. It excludes investment returns and tax effects. DSCR divides annual NOI by annual debt service. Interest-only math does not repay principal.
Rates and geography
National PMMS observations retain their dates and source attribution. They are not city offers or APRs. Observations older than fourteen days are labeled stale and cannot be copied into a calculator using the benchmark shortcut. City portals do not silently apply a city premium, tax rate, median price or insurance average. Cities with ambiguous state identity require a location check.
Operator and service scope
MITEY U.S. is a working educational planning platform. This workspace does not represent a licensed U.S. lender or mortgage broker, make credit decisions or accept mortgage applications. Optional educational enquiries go to the MITEY team. No licensed-provider introduction is implied. Commercial relationships, licensed coverage and enquiry routing must be confirmed before those services are offered.
The universal studio
The expanded studio includes holding-period quote costs, rent/buy investment opportunity cost, ARM caps, HELOC phases, construction draws and balloon debt. Each workspace publishes its own formula, inputs, exclusions and official guidance. These methods also power the public API and MCP.
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