Appraisal adjustment calculator
Enter the subject and one comparable, set your market-derived rates, and see the gross living area, pool, and garage adjustments applied to the comparable's sale price. The rates are prefilled with the defaults CompShield uses in its sample analysis — replace them with rates you have derived from your own market.
GLA adjustment
-$5,850
Pool adjustment
$0
Garage adjustment
$0
Net adjustment
-$5,850
Adjusted sale price
$506,150
How each adjustment is derived
Each adjustment is the difference between the subject and the comparable in one element, multiplied by the contributory value of that element in the local market. The sign convention runs toward the subject: a positive adjustment means the comparable is inferior to the subject in that element, so its sale price is adjusted upward.
- Gross living area: (subject GLA − comparable GLA) × rate per square foot. With the values above, that is 2180 − 2310 = -130 sq ft × $45 = -$5,850.
- Pool: a lump-sum adjustment applied only when one property has an in-ground pool and the other does not. Contributory value is usually well below installed cost.
- Garage: (subject bays − comparable bays) × rate per bay.
Gross adjustment here is 1.1% of the comparable's sale price. A high gross percentage is a signal that the comparable may not be the most similar sale available, regardless of how close the adjusted value lands.
The rates matter more than the arithmetic. See how regression derives adjustment rates and how paired sales analysis compares.
See a full comparable grid and addendumCompShield is an analytical support tool and does not replace the appraiser's professional judgment. The appraiser remains responsible for data selection, methodology, analysis, conclusions, and compliance with applicable appraisal standards.