The home affordability calculator uses the 28/36 rule to determine the maximum home price you can responsibly afford. The front-end ratio limits housing costs to 28% of gross monthly income, while the back-end ratio limits total debt payments to 36%. This prevents you from becoming house-poor.
Lenders look at two key ratios: your front-end ratio (housing costs ÷ gross income, max 28%) and back-end ratio (all debts ÷ gross income, max 36%). FHA loans allow higher ratios (31/43), but that doesn't mean you should max them out.
Your down payment dramatically affects affordability. On a $400,000 home, 20% down ($80,000) avoids PMI and gives a $320,000 mortgage. With 5% down ($20,000), you're financing $380,000 plus
Don't forget hidden costs: property taxes (0.5-2.5% of home value annually), homeowner's insurance (
This calculator earns its keep at decision points: before accepting a loan, comparing investment platforms, or negotiating salary. The difference between the headline figure and the true cost or return is only visible with accurate arithmetic.
A frequent error is using annual rates where monthly rates are required (or vice versa). Simply dividing an annual rate by 12 is only an approximation — the correct conversion for compound calculations uses the (1 + r)^(1/12) − 1 formula.
A first-time buyer models three scenarios before making an offer: 10%, 15%, and 20% deposit on a £280,000 property. The calculator shows exactly how the monthly payment and total interest cost change with each deposit level, making the decision visible rather than speculative.
Maximum Affordable Home Price
Max Price = (Monthly Income × 0.28 − Taxes − Insurance − PMI) ÷ (Monthly Mortgage Rate Factor) + Down Payment
Monthly Income × 0.28 gives your maximum housing payment (28% rule). Subtract estimated taxes, insurance, and PMI to get the maximum mortgage payment, then calculate the loan amount that payment supports.
Household income
Result: Maximum affordable home price: ~$417,000 with 14.4% down. Monthly payment: $2,800 total (mortgage + tax + insurance).
With 20% down and 6.5% rate: approximately $350,000-$400,000. With 10% down: $300,000-$350,000. Exact amount depends on debts, taxes, and insurance in your area.
Housing costs should not exceed 28% of gross income (front-end ratio), and total debt payments should not exceed 36% (back-end ratio). These are the standard qualifying ratios used by conventional mortgage lenders.
Conventional loans require 3-20%. FHA loans require 3.5%. VA loans require 0%. However, 20% down avoids Private Mortgage Insurance (PMI), which can cost
No. Banks approve based on debt ratios, not your comfort level. A mortgage at 28% of income leaves little room for emergencies, repairs, or lifestyle. Aim for 20-25% for financial flexibility.
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