How the CarmaDeal Score works
Every score is computed by a deterministic formula — the same inputs always produce the same score. No hidden judgment calls.
The formula
| Factor | Weight | What it measures |
|---|---|---|
| Asking price vs. market range | 45% | The price against live comparable listings near your ZIP, adjusted for seller type, CPO status, and condition |
| Mileage vs. expected | 15% | Odometer vs. ~12,000 miles/year for the model year |
| Accident, title & ownership history | 15% | Title brands (salvage/rebuilt/flood), reported accidents, owner count |
| Recall & safety flags | 10% | Model-level NHTSA recall campaigns and complaint volume; only a VIN-verified result is treated as open for that vehicle |
| Estimated 5-year cost | 10% | Projected fuel, insurance, and maintenance relative to price |
| Listing transparency | 5% | Penalty when critical details (VIN, mileage, trim…) are omitted |
Score bands
| Score | Tier | Guidance |
|---|---|---|
| 90–100 | Excellent Deal | Strong buy candidate — verify inspection & out-the-door fees |
| 75–89 | Good Deal | Reasonable price — light negotiation recommended |
| 60–74 | Fair Deal | Market-aligned — compare alternatives |
| 40–59 | Weak Deal | Likely overpriced or carrying notable risk |
| 0–39 | Avoid / High Risk | Materially unfavorable pricing or history |
Vehicle history & optional consolidation
The 15% history factor of the Deal Score is not scored by default — its weight is redistributed across verified factors because listing claims about accidents and title status are unverified. Vehicle History Analysis remains a separate report: upload the seller's CARFAX or AutoCheck to the history report analyzer for deterministic findings with page citations. When an account has both reports for the exact same 17-character VIN, CarmaDeal asks for explicit consent before creating a new consolidated report. It never overwrites either original and never averages two scores; it reruns the stored deterministic Deal Score input after replacing only the unverified history factor. Critical history findings remain non-compensatory and can cap the consolidated decision score. A numeric consolidated score is withheld when the market snapshot is stale, fewer than three comparable listings support it, the history report is stale, or history evidence confidence is too low. AI narrative is never used as a scoring input.
How your report is built
We license commercial automotive data feeds used across the industry and combine them with federal safety and fuel-economy data. We don't publish our specific vendor list.
Confidence & when we refuse to score
Every score carries a confidence level based on comparable-listing count: High (20+), Medium (8–19), Low (3–7). Below 3 comparables we withhold the score entirely rather than guess — you'll see "Insufficient data to provide a confident score for this specific trim/location."