Assumptions this tool makes. Both ends of the trade are inputs rather than findings. No federal agency publishes a national average closing cost rate, and what a seller pays is set by the listing agreement, by state law and by negotiation, so the defaults of 3% for buying and 6% for selling are where a reader starts rather than what this site asserts; replace them with the figures on your own Loan Estimate and your own listing agreement and every number on the page moves. Buying costs are treated as money spent at closing and are not financed into the loan; when they are financed the interest they create is a real extra cost and this page does not compute it. Excluded entirely are the loan's interest and principal, property taxes, homeowners insurance, maintenance, HOA dues and the cost of moving: those are financing and holding costs, not transaction costs, and principal in particular is excluded because it comes back on a sale while a fee does not. The price the house has to reach assumes the whole round trip is carried by the price of the house, which holds when nothing else about the property changes between the purchase and the sale; it is not a forecast and it does not allow for improvements, for depreciation, or for a market in which the house sells for less than was paid. Growth compounds monthly at one twelfth of the annual rate entered, a convention registered in the data ledger, which makes twelve monthly steps of 2.6% compound to 2.63% over a year. The default rate of price growth is the twelve-month change in the FHFA House Price Index to July 2026, a national repeat-sales average rather than a forecast, and the same release reports twelve-month changes from 0.6% in the Mountain division to 6.3% in the Middle Atlantic, which is why one national figure is shown as a single rung of a ladder. The month reported is the first month in which the value reaches the line, not the month whose value is nearest to it. Transfer taxes and recording fees differ by state and are not modelled. The years before you sell decide whether the sale happens before or after the month the price reaches the line; they do not move that month.