How HomeReadyCalc estimates your numbers
Every output you see comes from a transparent formula and a published, editable assumption. No black boxes. No teaser math. Here’s exactly what drives each calculator.
Our principles
Three rules every calculator follows.
Show the full picture, not the teaser number
Every monthly payment we display is PITI by default — principal, interest, property taxes, and homeowners insurance — plus PMI and HOA when they apply. No decorative "principal and interest only" figures that set buyers up for surprise.
Use conservative, defensible defaults
We start from national averages sourced from public data (Census Bureau, Federal Reserve, Freddie Mac). Where ranges vary widely, we choose a realistic midpoint so first-time buyers don’t get a falsely low number.
Let you override every assumption
Every calculator exposes the inputs driving its output — rate, tax rate, insurance rate, PMI rate, HOA. Change them to match a quote you’ve received or numbers specific to your market.
Default assumptions
The numbers we use — and where they come from.
These values pre-fill every calculator. You can override any of them on the calculator page.
| Assumption | Default | Why we use it |
|---|---|---|
| Property tax rate | 1.1% of home value per year | Close to the U.S. national average. Actual rates vary widely by state and county (e.g., ~0.3% in Hawaii vs. ~2.2% in New Jersey). Override on any calculator. |
| Homeowners insurance | 0.35% of home value per year | Roughly $1,400/year on a $400,000 home. Premiums depend on location, build, coverage limits, and deductible. Your lender will show the actual quote. |
| PMI (when down payment < 20%) | 0.5% – 1.0% of loan per year | We default to ~0.75% for a 10% down payment, a common midpoint. PMI drops off automatically once you reach 78% LTV — or you can request removal at 80%. |
| Closing costs | 2% – 5% of purchase price | Includes lender fees, title insurance, escrow, and prepaid taxes/insurance. Higher-cost states and first-year escrows push this closer to 5%. |
| Loan term | 30 years (fixed rate) | The most common term for first-time buyers. You can model 15- or 20-year terms in the mortgage calculator. |
| HOA dues | $0/month by default | Only applies to condos, townhomes, or planned communities. Add your actual monthly HOA to see it reflected in PITIA. |
The math
The formulas behind each calculator.
Monthly principal & interest
L = loan amount, r = monthly rate (APR / 12), n = term in months. If you put less than 20% down, PMI is added until your loan-to-value reaches 80%.
Affordability (28/36 rule)
We solve both constraints and pick the more restrictive one so your price reflects your actual debt profile, not just income. Adjustable DTI is supported on the calculator.
Closing costs
Includes origination and underwriting, appraisal, title insurance, recording fees, first-year home insurance premium, and escrow reserves. Split between fixed items and variable items based on purchase price.
Important: these are estimates, not quotes.
HomeReadyCalc provides educational estimates based on the assumptions above. They are not lender quotes, commitments, or legal/tax advice. Your actual rate, payment, and closing costs will depend on your credit profile, property location, loan program, and the lender you choose. Always confirm numbers with a licensed lender or advisor before making a purchase.