Housing

Housing decisions are usually the biggest numbers most people ever compare. These calculators run the real math on renting, buying, and loan terms — and the terms below explain the vocabulary lenders and listings assume you already know.

Housing calculators

Rent vs Buy

See what's cheaper in real terms, after mortgage costs, equity built, and the opportunity cost of your down payment.

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15-Year vs 30-Year Mortgage

See which loan term really costs less, using current Freddie Mac rates and the invest-the-difference math.

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Key terms

The vocabulary that comes up across housing decisions — this site is built to help you see the fuller picture, not just crunch numbers.

Equity: The part of your home you actually own — its value minus what you still owe on the mortgage.
Amortization: How a loan payment splits between interest and principal, shifting more to principal over time.
Principal vs interest: Principal is what you borrowed; interest is the cost of borrowing it.
Opportunity cost: What you give up by tying up cash in one thing instead of investing it elsewhere.
Down payment: The upfront cash you put toward a home purchase, reducing how much you finance.
PMI: Private Mortgage Insurance — usually required if your down payment is under 20%, and it protects the lender, not you.
Closing costs: One-time fees (title, appraisal, and more) paid when a home purchase or refinance closes, typically 2-5% of the loan.
Escrow: An account your lender uses to collect and pay your property tax and insurance for you.
Fixed vs adjustable rate: A fixed rate never changes; an adjustable rate (ARM) can rise or fall after an initial period.
Refinancing: Replacing your existing mortgage with a new one, usually to get a better rate or different terms.
Rate lock-in effect: Why many homeowners keep old, low-rate mortgages instead of refinancing or moving.