Home Buying Calculators: Down Payment, Closing Costs, Mortgage & Equity
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Buying a home in the US comes down to four numbers: the down payment, closing costs and cash to close, the monthly mortgage payment, and the equity you build. Each step below shows the formula lenders use, a worked example in US dollars, a government source, and a free calculator.
Home buying calculator: all four numbers at once
- Down payment$80,000Price × 20% · loan $320,000Refine in the full calculator
- Total closing costs (J)$10,200Loan costs (D) $6,000 + other costs (I) $4,200 − lender credits · cash to close ≈ $85,200Refine in the full calculator
- Monthly principal & interest$2,02330-yr fixed at 6.5% (taxes, insurance, PMI not included)Refine in the full calculator
- Starting home equity$80,000Home value − loan balance (20%)Refine in the full calculator
Section letters follow the CFPB Loan Estimate (lenders must send it within 3 business days of your application). Starting values are sample figures — replace them with your own Loan Estimate. This is an estimate, not a loan offer.
1. Down payment: how much to put down
Your loan amount is the price minus your down payment. On a conventional loan, putting down less than 20% usually means paying private mortgage insurance (PMI) until the balance reaches a set share of the original value.
Down payment = price × down payment %; Loan amount = price − down payment; LTV = loan ÷ price
Example: $400,000 × 10% = $40,000 down → $360,000 loan, 90% LTV (PMI likely).
Source: CFPB — What is private mortgage insurance?
Use the Down Payment Calculator2. Closing costs and cash to close
Closing costs are loan charges, third-party services, taxes and government fees, prepaids and initial escrow deposits. Your lender must send a Loan Estimate within three business days of your application, and a Closing Disclosure at least three business days before closing.
Cash to close ≈ down payment + closing costs − earnest money − seller/lender credits
Example: $40,000 + $11,000 − $5,000 − $3,000 = $43,000 due at closing (use your Loan Estimate's figures).
Source: CFPB — Loan Estimate explainer
Use the Closing Cost CalculatorGo deeper: closing costs topic hub
3. Monthly mortgage payment
Principal and interest follow the standard amortization formula. Your full payment usually adds property tax, homeowners insurance and any mortgage insurance collected in escrow.
M = P × r(1 + r)^n ÷ [(1 + r)^n − 1] (r = annual rate ÷ 12, n = months)
Example: $360,000 at 6.5% for 30 years → about $2,275 principal and interest, before taxes and insurance.
Source: CFPB — What is included in a monthly mortgage payment?
Use the Mortgage CalculatorGo deeper: property tax topic hub · how to calculate mortgage payments and interest
4. Home equity you build
Equity grows as payments reduce the balance and as market value changes. Lenders typically look at combined loan-to-value when you borrow against it.
Equity = market value − all loan balances; CLTV = total balances ÷ value
Example: $420,000 value − $330,000 owed = $90,000 equity, CLTV ≈ 78.6%.
Source: CFPB — What is a home equity loan?
Use the Home Equity CalculatorCommon home buying questions
How much do I need for a down payment on a house?
It depends on the loan: some programs allow 3%–3.5% down, VA and USDA loans can allow 0%, and conventional loans under 20% down usually require PMI. Down payment = price × your chosen percentage.
How are closing costs calculated?
They are the sum of itemized lender charges, third-party services, taxes and government fees, prepaids and initial escrow listed on your Loan Estimate. Cash to close adds your down payment and subtracts deposits and credits.
How do I calculate my monthly mortgage payment?
Use M = P × r(1 + r)^n ÷ [(1 + r)^n − 1] for principal and interest, then add monthly property tax, homeowners insurance and mortgage insurance if escrowed.
How do I calculate home equity?
Subtract every balance secured by the home from its current market value.