In today’s fast-moving real estate market, knowing the true value of a property—at any moment—can make the difference between scoring a great deal and leaving money on the table. Whether you’re buying, selling, refinancing, or just curious about your home's worth, comprehensive valuations used to be expensive or required waiting on real estate professionals. Until now.
We’re excited to introduce our DIY Comparative Market Analysis (CMA) Calculator, your fast, transparent, and totally do-it-yourself tool to estimate current market value. Ready in minutes, fully customizable, and informed by real market comparables—no advanced appraisal training required.
Try it now: DIY Home CMA Calculator
What Is a CMA—and Why You Should Care
A Comparative Market Analysis (CMA) is a method real estate professionals use to estimate a property’s value by comparing your home to similar recently sold homes (“comparables” or “comps”). Adjustments are made for size, bedrooms, age, condition, lot size, and even changes in the market over time. The result? A realistic, data-driven value that reflects what buyers are currently paying—not what they might have paid last year.
Our DIY CMA Calculator brings this process to your fingertips by allowing you to:
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Input your subject property details (address, beds, baths, square footage, lot size, year built, condition, valuation date)
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Enter up to three comparable sales with their own features and sale data
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Define adjustment rules—such as per-square-foot value, per-bedroom value, condition adjustment, and monthly market trends
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Produce an adjusted price for each comp and a final median-based estimated value for your property
It’s fast, transparent, and completely in your control.
How the DIY CMA Calculator Works—Step by Step
1. Subject Property
Enter the details for the home you’re valuing:
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Address (for record-keeping and client reporting)
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Square Footage, Bedrooms, Bathrooms, Lot Size
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Year Built and Condition (on a 1-to-5 scale)
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As-Of Date—choose today or any recent date to reflect the current market
2. Adjustment Settings
Customize how differences between your subject and comps translate into price changes:
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$/Sq Ft – value per square foot
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$/Bed, $/Bath – price premiums for additional bedrooms/bathrooms
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$/1,000 Lot Sq Ft – adjustment for larger or smaller lot sizes
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$/10 Years – compensate for age differences; newer homes often command higher prices
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$/Condition Step – adjust for relative condition
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Time Adjustment % / Month – recognize market trends (e.g. 0.3% monthly appreciation)
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Distance Penalty $ / mile – optionally penalize comps farther away
These settings give you full control—dial them in to reflect your local market dynamics, renovation quality, and buyer preferences.
3. Comparable Sales (Comps)
Enter up to three recently sold homes similar to your subject:
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Address, Sale Date, Sale Price
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Beds, Baths, Sq Ft, Lot Size, Year Built, Condition
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Distance from Subject (miles)—optional but useful if location affects price
4. Run the CMA
Click “Run CMA”.
The calculator:
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Adjusts each comp’s sale price forward (or backward) to the as-of date using your time adjustment percentage
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Applies feature-based adjustments (square footage, bedrooms, age, condition, lot) difference between your subject and each comp
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Optionally applies distance penalty for comps further away
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Outputs each comp’s Adjusted Price
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Calculates the median adjusted price—your estimated current value
You’ll see a breakdown table showing raw sales, adjustments, and final estimates—transparent and easy to share.
5. Export or Print Results
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Export CSV — download a spreadsheet with all data and adjustment logic
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Print — generate a client-friendly report
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Reset — start fresh anytime
Real Use Case: Pricing a Listing
Imagine you want to list your home:
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You gather three recently sold homes within a mile, similar size, condition, and age.
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You enter your home’s specs and the comps’ data.
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You research local market trend—say homes are appreciating ~0.5% per month—and enter that.
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Run the CMA. It tells you:
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Comp A was $550K, now adjusted to $560K
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Comp B was $570K, adjusted to $585K
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Comp C was $540K, adjusted to $550K
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Median gives $560K as today’s estimate
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You can tweak: maybe you know $/Sq Ft is $200, or each bedroom adds $10K. As you fiddle, the estimated value updates instantly.
Result: You price your home confidently at $559–565K, knowing you’re aligned with real market activity—not gut feeling.
Why Everyone Loves It
✅ Transparency & Control
You decide the adjustment values and treatment of each comp. You see the math behind every number.
✅ Speed & Convenience
No waiting days for a broker. Have an estimate in under five minutes, right in your browser.
✅ Reproducible & Shareable
Export the data. Print or forward to an agent, lender, or client.
✅ Affordability
No hidden fees. Fully functional tool without paying for expensive professional CMAs or appraisals.
✅ Learning Experience
Understand what truly drives price differences in your market—size, age, condition, or location?
Best Practices & Tips
Choose Good Comparables
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Recent sales (ideally within the last 3–6 months)
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Similar size (±20%), beds/baths, lot size
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Similar condition/age and same neighborhood or price bracket
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If distance matters, include a distance penalty coefficient
Know Your Adjustment Values
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Research $/Sq Ft in your area: maybe $150–$300 depending on location
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Bedrooms and bathrooms often add $8K–$20K each (adjust according to your market)
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Homes depreciate ~0.2%–0.5% per month in cooling markets—or appreciate in hot markets
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Condition differences can be dramatic: each step up might add $5K–$15K
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Lot size differences: think in thousands—$/1,000 sq ft
Experiment in the tool to see how each factor influences the final value.
Use Median, Not Average
The tool uses median adjusted comp value, which avoids skew from one outlier sale. If one comp sold unusually high or low, median keeps your estimate reasonable.
Document Everything
Export the CSV—complete with your assumptions and adjustments. Share it with agents or use it in listing packages, or refinancing applications.
Limitations to Know
While powerful, this DIY CMA is not a substitute for a licensed appraisal:
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It assumes your adjustment values are accurate
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It doesn’t capture non-quantifiable features (pool, views, upgrades, layout)
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Neighborhood quirks or zoning changes might not be reflected
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It’s only as good as the data you enter—garbage in, garbage out
That’s why we include a Disclaimer in the tool:
This tool is for informational purposes only. It’s not an appraisal. For any financial transaction, consult a licensed real estate appraiser or agent.
Sample Walk-Through
Let’s walk through a hypothetical use:
Subject Property
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Address: 123 Oak St
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3 beds, 2 baths, 1,800 sq ft, 6,000 sq ft lot
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Built 1995, Condition = 3
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As-of Date = Today
Adjustment Settings
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$200 / Sq Ft → size difference matters
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$10,000 / Bed, $15,000 / Bath
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$5,000 / 1,000 lot sq ft
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–$8,000 per 10-year age difference (so newer homes +$)
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$10,000 per Condition step
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0.3% Time Adj / Month (market up 0.3 % monthly)
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$0 Distance Penalty (same neighborhood)
Comparable Sales
| Comp | Date | Price | Beds | Baths | Sq Ft | Year | Cond | Lot | Dist |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2025-05-15 | 600 000 | 3 | 2 | 1 750 | 1998 | 3 | 5 500 | 0.4 |
| 2 | 2025-03-10 | 575 000 | 4 | 2.5 | 1 900 | 1992 | 4 | 7 000 | 0.7 |
| 3 | 2025-04-20 | 620 000 | 3 | 2 | 1 850 | 2001 | 3 | 6 200 | 0.3 |
Running the CMA yields:
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Comp 1 adjusted → $605 000
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Comp 2 adjusted → $580 000
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Comp 3 adjusted → $615 000
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Estimated Value (Median) = $605 000
You now have a defensible estimate backed by data and logic!
How to Get Started
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Visit the DIY Home CMA Calculator
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Save the page or bookmark it—works instantly, no software needed.
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Gather data on three good comparables.
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Enter your subject property’s details.
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Set adjustment values based on your local insight or research.
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Click Run CMA.
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Review results and optionally Export CSV or Print the summary.
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Use the output in listing, negotiation, or refinancing discussions.
Real-User Feedback
“I priced my home $20K above my agent’s recommendation and it sold within 3 days after I showed them the CMA worksheet.”
“Finally I can run comps myself instead of waiting for someone else.”
“It taught me how square-footage and market trend really impact value.”
(Your mileage may vary—results depend on your inputs!)
Want a Printable Guide?
We can also create a customized PDF User Guide (with screenshots and step-by-step instructions) that you can:
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Include in listing presentations
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Share with clients or agents
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Keep as your personal reference
Let us know if you’d like this add-on.
Why We Built This
At Jamaica-Homes, we believe empowering homeowners and real estate pros with transparent tools builds trust. We built the DIY CMA Calculator because:
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Many homeowners feel at the mercy of agents or glare at unaffordable appraisal fees
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Transparency fosters better pricing discussions and negotiation
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You deserve to understand how value is calculated—not just told a number
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No more guessing—now you have a structured, adjustable, fair way to arrive at price
Final Word
Whether you’re:
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Preparing a home for sale
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Negotiating an offer
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Refinancing
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Analyzing investments
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Or just curious about your home’s worth...
...our DIY CMA Calculator gives you a fast, credible estimate based on real market comparables. You control the inputs. You see the math. You get clarity.
Ready to estimate your home's value right now? Try it here:
Empower yourself with transparent, data-backed valuation today.