Tools

• Shorten the term before you shop the rate. Moving 30 years to 15 on this loan roughly halves total interest, because you are borrowing the same money for half as long. The payment rises, so check it against the affordability tab first.
• Extra principal compounds early. A payment made in year one avoids interest for all remaining years; the same payment in year twenty avoids almost none. Put the extra field above to work and watch the payoff figure move.
• Pay every two weeks. Twenty-six half-payments a year equals thirteen monthly payments, not twelve — a full extra payment against principal without it feeling like one. Confirm your servicer applies it immediately rather than holding it.
• Your rate is set by your profile, not the headline. Credit band and loan-to-value move the rate more than shopping does. The rates page shows the current 30-year conforming index split by credit score and LTV so you can see what each tier actually costs.
• Crossing 80% loan-to-value removes mortgage insurance. That is a separate saving from interest, and it is often the highest-return use of a few extra thousand at closing.
• Do not restart the clock. Refinancing into a fresh 30-year term can lower the payment while raising lifetime cost. The refinance tab flags this explicitly.

Interest is not a fee you pay once. It accrues on whatever balance remains, which is why anything that reduces the balance sooner has an outsized effect.

Lenders test two ratios. The front-end ratio is housing cost alone against gross income. The back-end ratio — the one that usually decides the file — is every monthly debt obligation including the proposed mortgage:

Housing payment means principal, interest, property taxes, insurance, mortgage insurance and any HOA dues — not the principal-and-interest figure shown on the first tab. Other debt means minimum credit-card payments, car and student loans, personal loans and child support. Utilities, groceries and insurance premiums are not counted.

Gross income is before tax. If you are self-employed, most lenders use a two-year average of net income after deductions, which is often well below what you actually bank.

• Pay down revolving balances, not instalment loans. Clearing a card removes its minimum payment from the ratio immediately. Paying extra on a car loan does not reduce the monthly minimum, so it does not help the ratio at all.
• Open no new credit while under way. A new account changes the minimum payments a lender sees and often triggers a re-underwrite. Many files are lost here, after approval.
• Season your reserves. Money that has sat in your account for two to three months counts cleanly. A recent large deposit has to be sourced and documented, and unsourced deposits get excluded.
• Two years of stable income is the usual bar. A job change within the same field is generally fine; a change of field, or moving to commission or self-employment, often restarts that clock.
• The programme sets the ceiling. Conventional loans typically stop near 45%, stretching toward 50% with strong credit and reserves. FHA can go higher with compensating factors. VA uses residual income rather than a hard DTI cap.
• Get more than one quote. Overlays differ — the same file can be declined by one lender and approved by another. Applications within a short window count as a single credit inquiry for scoring.

• Underwrite the expenses you cannot see. The common error is counting only taxes, insurance and the mortgage. Budget separately for vacancy, ongoing maintenance, and capital items — roof, HVAC, water heater — which arrive rarely and cost a great deal when they do.
• Cap rate and cash-on-cash answer different questions. Cap rate ignores financing and lets you compare properties against each other. Cash-on-cash includes the loan and tells you what your actual cash is earning. A property can look strong on one and poor on the other.
• The 1% rule is a filter, not a verdict. Monthly rent near 1% of price is a fast way to discard obviously weak deals. It says nothing about taxes, insurance or condition, which is where returns are usually decided.
• Thin cash flow is fragile. A property clearing a small monthly surplus is one vacancy or one repair from negative for the year. Stress it: raise vacancy, add a month empty, and see whether it still works.
• Investment financing costs more. Expect a higher rate and a larger deposit than an owner-occupied loan, and expect most lenders to want six months of reserves per property.
• Rent is set by the market, not your spreadsheet. Check what comparable units actually let for nearby before trusting any projection — including this one.

• Compare break-even against how long you will hold. If break-even is 30 months and you expect to sell or refinance inside two years, the costs are never recovered no matter how good the rate looks.
• Watch the term reset. Refinancing 24 years remaining into a fresh 30-year term lowers the payment while adding six years of interest. Ask for a term matched to what you have left; the calculator above flags when lifetime cost rises.
• A no-cost refinance is not free. The fees are financed into the balance or bought with a higher rate. That can still be right if you expect to move soon, but compare total cost rather than the headline.
• Cash-out is priced higher than rate-and-term. Taking equity out generally carries a rate premium and tighter LTV limits, so quote the two separately rather than assuming one rate covers both.
• Reaching 80% LTV can matter more than the rate. If appreciation or principal paydown has taken you under 80%, dropping mortgage insurance may save more than the rate change — and sometimes needs only a new appraisal, not a refinance.
• Rate is not the whole quote. Compare points and lender fees alongside it. A lower rate bought with points only pays off if you hold long enough to recover them.