Calculator inputs
Formula used
Down payment = Property Price × 20%
Loan amount = Property Price − Down Payment
Closing costs = Property Price × Closing Cost %
Cash to close = Down Payment + Closing Costs
Monthly principal and interest = P × [r(1+r)n] ÷ [(1+r)n−1]
P is loan amount, r is monthly interest rate, and n is total monthly payments.
Base monthly housing cost = Principal and Interest + Monthly Tax + Monthly Insurance + HOA + PMI + Maintenance Reserve
Front-end ratio = Base Monthly Housing Cost ÷ Gross Monthly Income × 100
Reserve months = (Liquid Savings − Cash to Close) ÷ Base Monthly Housing Cost
How to use this calculator
- Enter the expected property price.
- Add an estimated closing cost percentage for your market.
- Provide your loan rate and term for mortgage payment estimates.
- Enter annual tax, annual insurance, HOA, and any PMI amount.
- Use maintenance percentage to reserve for repairs and upkeep.
- Add income and savings to check affordability and remaining reserves.
- Optionally include an extra monthly payment to see a faster payoff budget.
- Press Calculate Now to show the result block above the form.
- Use the CSV or PDF buttons after calculation to export the summary.
Example data table
| Field | Example value |
|---|---|
| Property price | $350,000.00 |
| Down payment | $70,000.00 |
| Closing costs | 3.00% ($10,500.00) |
| Loan amount | $280,000.00 |
| Interest rate and term | 6.75% for 30 years |
| Property tax | $4,200.00 yearly |
| Insurance | $1,800.00 yearly |
| HOA | $120.00 monthly |
| Maintenance reserve | 1.00% yearly ($291.67 monthly) |
| Base monthly housing cost | $2,727.74 |
| Cash needed at closing | $80,500.00 |
| Reserve months after closing | 7.15 months |
Frequently asked questions
1. Why do buyers often target 20 percent down?
Twenty percent down usually lowers the loan balance, reduces monthly payments, and may eliminate PMI. It can also strengthen an offer by showing stronger financing.
2. Does this calculator include closing costs?
Yes. It estimates closing costs using your chosen percentage, then adds that amount to the 20 percent down payment to show total cash needed at closing.
3. What monthly costs are included?
The base monthly estimate includes principal, interest, property tax, insurance, HOA, PMI, and a maintenance reserve. This creates a broader ownership view than mortgage payment alone.
4. Why is PMI still an input here?
Some buyers compare scenarios, face lender-specific rules, or enter a smaller effective equity position. Keeping PMI editable makes the calculator more flexible for planning and what-if testing.
5. What is the front-end ratio?
The front-end ratio measures housing cost against gross monthly income. Many lenders prefer it near or below 28 percent, though exact limits vary by loan type.
6. What are reserve months after closing?
Reserve months estimate how long your leftover liquid savings could cover the base monthly housing cost after paying your down payment and closing costs.
7. Can this replace a lender quote?
No. This is a planning tool. Taxes, insurance, rate locks, prepaid items, credits, and lender fees can all change the final numbers on an official estimate.
8. When should I use the extra payment field?
Use it when you plan to pay extra principal each month. It helps you budget a higher monthly outflow, even though the core mortgage formula stays unchanged.