THE NUMORIX GUIDE
How to use the Closing Costs Calculator
Last reviewed September 14, 2026
What this calculator does
The estimate applies buyerRatePercent and sellerRatePercent to purchase price, adds buyer fixed costs and prepaids to the buyer percentage costs, and adds seller fixed costs to seller percentage costs.
Formula and method
The estimate applies buyerRatePercent and sellerRatePercent to purchase price, adds buyer fixed costs and prepaids to the buyer percentage costs, and adds seller fixed costs to seller percentage costs. Loan amount is purchase price minus down payment; buyer cash to close is down payment plus buyer total.
Variables and inputs
Enter purchase price, down payment, buyer and seller percentage rates, buyer and seller fixed costs, and buyer prepaids. Every input is a dollar amount except the two cost rates, which are percentages. The engine rejects nonfinite values and a down payment above purchase price.
Worked example
For a $400,000 purchase with $80,000 down, buyer rate 3%, seller rate 1.5%, buyer fixed costs $1,500, seller fixed costs $1,000, and buyer prepaids $2,500, buyer percentage costs are 400,000 x 0.03 = $12,000. Buyer total is 12,000 + 1,500 + 2,500 = $16,000, seller total is 400,000 x 0.015 + 1,000 = $7,000, and buyer cash to close is 80,000 + 16,000 = $96,000.
How to interpret the result
Buyer and seller estimates are shown separately because who pays a charge depends on the contract and local practice. Cash to close combines the down payment with the modeled buyer costs; it is not the same as the loan amount or total transaction price.
Common mistakes to avoid
Enter percentage rates as numbers such as 3, not 0.03. Do not subtract buyer costs from the down payment. Check whether a lender or seller credit offsets a charge before treating the estimate as cash required.
Assumptions and limitations
The route uses two percentage buckets, fixed buckets, and buyer prepaids only. It excludes lender-specific line items, title and recording fees, transfer taxes, prorations, credits, escrow cushions, inspections, and local contract rules. Replace assumptions with the official disclosure when available.