Mortgage guides
Explanations of the rules behind the calculators, with a worked example and the official source.
By the Crunch My Mortgage Editorial Team. Last updated .
Crunch My Mortgage publishes a guide when a question can be answered from a formula or from a government document. Each guide names the rule, walks one example with a calculator on this site, and links the official source. A guide is not a rate quote and not a loan offer.
- FHA loan limits in 2026. HUD’s 2026 floor, ceiling, and special-exception limits, and what they do not include.
- Who is exempt from the VA funding fee. Who pays no VA funding fee, and what an exemption does not waive.
- VA loan closing costs. The funding fee, the charges VA lets a veteran pay, and a worked example.
- Debt-to-income limits by loan type. Front-end and back-end ratios, and the cutoffs Fannie Mae, FHA, and VA publish.
- How to read a Loan Estimate. What each page of the Loan Estimate is for, and how cash to close differs from closing costs.
- When PMI comes off: 80% and 78%. The 80% cancellation request, the 78% automatic end, and why FHA MIP is different.
- Mortgage glossary. Short definitions of the terms the calculators use, with a link to the page that does the math.
- How much house $50k, $75k, $100k, and $150k can support. Four incomes, one set of typed limits, and the price each one supports.
- Cash to close vs closing costs. The two boxes on the Loan Estimate, and why quoting one of them answers a different question.
- How to compare two mortgage offers. Note rate, APR, points, and the cost over the years the loan is kept.
- When FHA mortgage insurance comes off. The 11-year end and the life-of-loan case, both set by the original loan-to-value ratio.
- PMI and FHA MIP, compared. Two premiums with different names, different agencies, and different ending rules.
- Mortgage recast vs refinance. A lower payment on the same note, set next to a new loan with its own costs.
- HELOC vs a home equity loan. A revolving line with a draw period, next to a lump-sum loan that amortizes immediately.
- Are biweekly mortgage payments worth it. The interest a 26-payment year saves, and what a third-party fee does to that result.
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