The direct answer
A CMA, a formal appraisal and an online automated estimate are different valuation processes with different scopes and evidence. Compare how each conclusion was produced rather than treating all three labels as equally precise property values.
Identify the process behind the label
A comparative market analysis organizes market evidence for a stated purpose. A formal appraisal follows a defined assignment scope and professional valuation process. An online value estimate can rely on automated data and assumptions that may not include current interior condition. The label alone does not reveal the exact evidence or scope, so request the basis and date before comparing conclusions.
To apply the approach to an editable scenario, use the Comparative Market Analysis (CMA) Calculator. For the neighboring question, explore Property Value Calculator.
Review condition, adjustments and missing information
An outdated condition assumption can create a gap even when sale records are otherwise relevant. Examine which comparables were selected and how differences were treated. The EstateCalcHub CMA tool does not connect to a property database: it combines already adjusted comparable indications entered by the user, plus an unweighted median and range for context. It does not produce a formal appraisal report.
Interpret disagreement as a question to investigate
Different dates, evidence sets or assignment purposes can explain different values. A median reduces the influence of extreme entered observations, but it cannot verify those observations. Review the supporting facts instead of averaging several unrelated conclusions and calling that result authoritative. The appropriate professional process depends on the actual purpose of the valuation.
Worked example
Entered adjusted values of $490,000, $510,000, $500,000 and $505,000 produce a $501,250 equal-weight indication. Sorting them gives a $502,500 median, and the range is $490,000 to $510,000. These are arithmetic summaries of supplied evidence, not three independently verified appraisals.
Open Comparative Market Analysis (CMA) Calculator and test your assumptions →
Common mistakes and limitations
Do not present a calculator output as a lender-approved valuation or assume that an automated estimate includes a recent renovation.
Does not access MLS and is not a licensed appraisal. Adjustments are supplied by the user.
Frequently asked questions
Does this CMA tool pull online home values?
No. All adjusted values and any custom weights are entered by the user.
Is the median the same as the weighted indication?
No. The median uses sorted values, while the weighted indication uses the chosen relative weights.
Sources and further reading
The article’s examples are illustrative arithmetic. The references below provide context for operating, valuation or transaction concepts; they do not endorse the assumptions or the calculator.
- IRS — Instructions for Form 709 (2025) — real property valuationComparable-sales concept and adjusting for differences in date, size, condition and location.
- IRS — Publication 551 (12/2025), Basis of AssetsFair-market-value concept and use of similar-property sales as evidence.
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