Real Estate Appraisal Calculator

The sales comparison approach is the primary method licensed appraisers use to value residential property: it estimates what a subject property is worth by analyzing recent sale prices of similar nearby homes, known as comparables or 'comps.' This calculator implements a simplified version of that approach using three comps' price-per-square-foot figures, averaged and applied to the subject property's own square footage.

Each comp's price-per-square-foot is its Sale Price divided by its own Sq Ft, so for a fixed sale price, a comp with a larger declared square footage produces a lower per-square-foot rate — the same dollar amount is simply being spread across more square feet. Since that rate feeds directly into the averaged rate applied to your subject property, an inflated comp square footage can meaningfully understate the resulting estimated value.

Average $/Sq Ft is the mean of all three comps' rates, while Median $/Sq Ft is the middle value of the three. The median is offered because a single unusually high or low comp — say, one in noticeably different condition or a different micro-location — can pull an average further off-center than it pulls a median, so comparing the two gives a quick sense of whether one comp is skewing the overall estimate.

Condition Adjustment applies a final percentage adjustment to the base value calculated from the average comp rate and subject square footage — a positive percentage increases Estimated Value to reflect the subject being in superior condition to the comps, and a negative percentage decreases it to reflect inferior condition, applied once after the comp-based average value is established. This calculator remains an estimation aid, not a substitute for a professional appraisal — a licensed appraiser typically analyzes more than three comps, verifies details on-site, and factors in lot characteristics, recent upgrades, market timing, and professional judgment that a simplified calculator like this one cannot replicate.

Value Range is the spread between the highest and lowest comp's price-per-square-foot rate, scaled to your subject property's square footage — a measure of how much the three comps disagree with each other. Low Estimate and High Estimate are Estimated Value minus and plus half of that spread, giving a plausible bracket rather than one precise number; widely divergent comps widen the bracket, while closely clustered comps narrow it. Low Estimate is floored at $0 so it can never show a nonsensical negative property value even when comps diverge sharply.