C Car Depreciation
20 brands · 94 models · 7 markets

How We Calculate Car Depreciation

Our depreciation calculator uses a five-step formula that blends model-specific resale data, mileage adjustment, country modifiers, generation effects, and accident history. This page documents exactly how each input shapes the final depreciation rate.

The five-step formula

Depreciation is not a single number — it is a compound of model behavior, owner usage, and market context. Each step below is applied in order to produce the final retained-value estimate.

01

Model-specific depreciation curve

Every model has its own 10-year depreciation curve, modeled from 18+ months of resale listings, auction data, and trade-in values across our 7 tracked markets. A Toyota Tacoma holds ~70% at 5 years; a BMW 7 Series holds ~32%.

02

Mileage adjustment

We benchmark each model against an expected-miles-per-year figure (typically 11,500–14,000). Every 1,000 miles above that baseline adds roughly 0.4–0.9% extra depreciation, scaled to the model's segment and typical usage pattern.

03

Country modifier

The same car depreciates at different speeds in different markets. Saudi Arabia and Canada slow depreciation on trucks and large SUVs; EU accelerates it on full-size sedans. We track the US, Canada, UK, EU, Australia, Saudi Arabia, and UAE.

04

Generation cliff

When a new generation launches, the outgoing generation drops 4–9% overnight and keeps depreciating 1–2% faster than its original curve predicted. Our calculator accounts for the generation boundary and applies the cliff automatically.

05

Accident history

A disclosed accident is the single largest driver of diminished value. We apply a three-tier adjustment — minor (paint/bumper), moderate (panel/airbag), major (frame/flood/salvage) — with per-model severity because luxury and premium brands are punished harder than mainstream ones.

A worked example

Take a $35,000 Toyota Camry XSE bought new in California, driven 18,000 miles per year, with one minor parking-lot bumper repair on its history.

  • 1 Curve: Camry retains 61% at year 5 → expected value $21,350.
  • 2 Mileage: 90,000 actual vs. 67,500 expected → extra 9% depreciation → $18,200.
  • 3 Country (US): baseline, no adjustment.
  • 4 Generation: mid-generation, no cliff applied.
  • 5 Accident (minor): −8% → final value $16,750.

Total depreciation: 52% over 5 years, or ~$3,650/year.

Data sources

We don't rely on a single data provider. Every curve is cross-checked against at least three independent sources before it ships.

  • Auction prices
    Manheim, ADESA, BCA and Copart wholesale auction results.
  • Retail listings
    Public dealer inventory pricing sampled weekly across all 7 markets.
  • Trade-in values
    Manufacturer trade-in offers and instant-cash-offer benchmarks.
  • KBB / Edmunds / CAP
    Published residual tables cross-checked against our curve every refresh.
  • Market reports
    Cox Automotive, J.D. Power, Auto Trader UK, and CarGurus quarterly depreciation reports.

What we don't model

Being honest about limits is part of the methodology. Our calculator is not a VIN-level valuation — it's a fair-market benchmark for a clean-title, average-condition example of the model you select. The following are excluded:

  • · Trim-level and option-package deltas below ±3% of MSRP
  • · Dealer-specific incentives or regional rebates
  • · Tax credit recapture on used-EV resale
  • · Aftermarket modifications (lift kits, wraps, tuning)
  • · Open recalls or unresolved TSBs on the specific VIN

Methodology FAQ

How often is the data updated?
Model curves are refreshed monthly. Country modifiers and accident-impact coefficients are audited quarterly. The calculator itself is versioned — any formula change is noted in the methodology changelog.
Why do your numbers differ from KBB or Edmunds?
KBB and Edmunds are priced for transactions in a single market (US retail). Our calculator blends wholesale, retail, and international resale to give a true fair-value depreciation rate. We typically land within 2–4% of KBB for US-spec mainstream models.
Are these numbers a guarantee of resale value?
No. Actual resale value depends on condition, local supply, trim, options, and timing. Our estimate is the mid-market expected value for a clean-title, average-mileage example. Treat it as a planning benchmark, not an offer.
How do you handle EVs and hybrids?
EV depreciation is modeled separately because battery age, range degradation, and tax-credit pass-through dominate the curve. We refresh EV curves every 60 days — they move much faster than ICE residuals.
Can I see the formula for a specific model?
Every model page shows the full 10-year curve, per-mile depreciation, and country-by-country adjustment. Click any model below or use the calculator on the homepage to run your own numbers.