Automotive Calculators

Straight-Line Car Depreciation Calculator

2026-09-24 7 min

Straight-line schedule for a car: yearly loss, book value at any age and loss share.

Book Value Now: $20428.57
Yearly Loss: $3857.14; $/yr
Lost So Far: $11571.43
Lost Share: 36.2; %

Calculator

Vehicle Cost($) Help

Purchase price

Salvage Value($) Help

End value

Useful Life(yrs) Help

yrs

Service years

Age Now(yrs) Help

yrs

Current age

Results update live as you type

Live statistics

Book Value Now

$20428.57

Yearly Loss

$3857.14

$/yr

Lost So Far

$11571.43

Lost Share

36.2

Results

Normal

Book Value Now

$20428.57

Scheduled value at this age

Yearly Loss

$3857.14$/yr

Even yearly drop

Lost So Far

$11571.43

Accumulated depreciation

Lost Share

36.2%

Share of cost gone

Standard amortization and depreciation math. Enter your own rate, term and prices for an exact figure.

Visualizations

Book sensitivity

22,743x0.8

21,586x0.9

20,429x1.0

19,271x1.1

18,114x1.2

Lost vs book

Lost so far36%

Book value64%

Book value

20,429$

050,000

Formula

How Straight-Line Car Depreciation Calculator is computed from its inputs, with every derived figure shown.

Book(age) = Cost - (Cost - Salvage) / Life x age

Alternative Form

Floored at salvage so book never goes negative.

Variables

Symbol	Name	Unit	Description
C	Cost	$	Purchase price
a	Age	yrs	Years elapsed

Explanation

Linear schedule from cost to salvage evaluated at the current age.

Derivation

Linear schedule from cost to salvage evaluated at the current age.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Set vehicle cost.

Vehicle Cost

Value:32000 $

Intermediate: 32000 $

Result: Accepted

Step 2

Set salvage value.

Salvage Value

Value:5000 $

Intermediate: 5000 $

Result: Accepted

Step 3

Set useful life.

Useful Life

Value:7 yrs

Intermediate: 7 yrs

Result: Accepted

Step 4

Set age now.

Age Now

Value:3 yrs

Intermediate: 3 yrs

Result: Accepted

Step 5

Spread the loss, multiply by age, subtract from cost.

Book(age) = Cost - (Cost - Salvage) / Life x age

Vehicle Cost:32000 $

Salvage Value:5000 $

Useful Life:7 yrs

Age Now:3 yrs

Intermediate: Book = Cost - Annual x Age

Result: Book = $20428.57

Final Answer

$20428.57

Worked Examples

See how the calculator works with different scenarios.

Scenario

$32,000 to $5,000 over 7 years, age 3.

Inputs

Vehicle Cost:32000 $

Salvage Value:5000 $

Useful Life:7 yrs

Age Now:3 yrs

Calculation

Linear schedule evaluated at current age.

Result

Books $20428.57 (36.2 % lost).

Interpretation

Mid-schedule book.

Understanding Your Result

Your Result: Book Value Now: $20428.57

Typical range: A $32,000 car to $5,000 salvage over 7 years books near $20,400 at age three.

What This Means

The scheduled value at any age on the even-loss method.

Why It Matters

Books, fleets and taxes run on straight-line schedules.

Professional Interpretation

Use market curves for sale timing; straight-line for books and budgets.

How the curve works

Declining-balance curves front-load losses like real markets; straight-line averages spread them evenly for budgeting.

What moves a car off the curve

Condition, history, mileage, options, region and market shocks all bend individual results around the average.

Recommendations

•Curve math replaces guesswork on future value
•Per-mile figures compare any two cars fairly
•Residual percentages anchor lease and buyout calls
•Segment rates keep forecasts realistic

Learn — fuel economy, deeply

Cars lose value fastest first: roughly 20 percent in year one, then about 10 to 15 percent yearly after. Calculators in this group model that curve as straight-line averages, declining-balance curves, per-mile costs or residual percentages, and turn any of them into resale, future value or cost-per-mile figures.

1 · Where the gallon goes (energy path)

Engine heat

60–70% lost

Coolant + exhaust carry most energy away. Hybrids recover some via Atkinson cycle + regen.

Driveline

5–15% lost

Transmission, differential, accessories. CVTs and 8–10 speed autos lose less.

Aero drag

∝ v²

Doubles from 55→78 mph. Roof boxes hurt more than trunks.

Rolling + brakes

10–20%

Tires, weight, stops. Regen braking (hybrid/EV) reclaims city braking energy.

2 · What EPA / WLTP ratings actually mean

City cycle — stop-and-go, 21 mph average, idle included. Hybrids shine here (regen + engine-off).
Highway cycle — steady 48 mph average with gentle accelerations. Aero and gearing dominate.
Combined — 55% city + 45% highway weighting. The single number most drivers should compare.
Real-world gap — expect 5–15% below the sticker with normal driving; hypermilers can beat it, aggressive drivers miss by 25%+.
MPGe — 33.7 kWh = 1 gallon-equivalent. A 120-MPGe EV uses ~⅓ the energy per mile of a 35-MPG car.

3 · Factor-impact table — what moves your number most

Factor	Typical impact	Why
Speed above 55 mph	−5 to −25%	Aero drag rises with v². Each 5 mph over 55 ≈ +$0.30–0.50/gal equivalent.
Aggressive driving	−10 to −30%	Hard acceleration + braking wastes kinetic energy, especially in the city.
Under-inflated tires (−5 PSI)	−2 to −4%	Higher rolling resistance. Check monthly; pressure drops ~1 PSI per 10°F.
Roof rack / cargo box	−5 to −25%	Empty rails ≈ −5%; loaded box at highway speed up to −25%.
Excess weight (+100 lb)	−1 to −2%	Matters most in stop-and-go. Clean the trunk before long trips.
A/C at city speed	−5 to −15%	At highway speed A/C beats open windows (drag). Use recirculation.
Cold weather (20°F vs 77°F)	−10 to −20%	Rich warm-up mixture, thicker fluids, winter-blend fuel, heater load.
Clogged air filter / bad O2 sensor	−4 to −40%	A failed oxygen sensor alone can cut economy by up to 40%.
Idling	0 mpg	0.2–0.5 gal/hr burned standing still. Restart beats 30 s+ idling.
E10 → E85 fuel switch	−15 to −30%	Ethanol carries less energy per gallon; flex-fuel range drops accordingly.

Winter playbook

• Expect −10 to −20% on short trips; combine errands on one warm engine.
• Tires lose ~1 PSI per 10°F — re-inflate monthly.
• Idle 30 s max, then drive gently; cabin heat comes faster under light load.
• Winter-blend fuel has slightly less energy — a 2–3% seasonal dip is normal.

Summer playbook

• City: windows down under ~45 mph; highway: A/C + recirculation beats open windows.
• Park in shade; ventilate before blasting A/C.
• Hot asphalt softens tires — still check pressure, heat raises it.
• Roof cargo hurts most in summer road-trip season — move it inside or to a hitch carrier.

4 · Measure like a pro (the 3-tank protocol)

Fill to first click at the same pump, record the odometer (Tank 0).
Drive normally for 2–3 tanks; always refill to first click at the same pump.
MPG = total miles ÷ total gallons across all tanks — averaging kills pump-click noise.
Cross-check with the trip computer; a persistent >10% gap means the computer needs calibration — or the car needs service.
Log with an OBD-II dongle for per-trip MPG if you want to isolate commute vs. highway behavior.

Practical Tips

•Buy the dip: 2 to 3 year old cars skip the steepest drop
•Compare depreciation per mile, not just total loss
•Check segment rates instead of generic 15 percent rules
•Favor colors, trims and records that resell well
•Mileage under 12,000 yearly protects residuals
•Refresh the forecast before each buy or sell decision

Common Mistakes

Using one rate for every car

Segment, brand and powertrain change the curve dramatically.

Ignoring mileage

An age-only figure overvalues high-mile cars badly.

Confusing trade value with resale

Trade bids run below private-party and retail figures.

Forgetting options fade

Expensive options rarely return their cost at resale.

Assumptions

This calculator makes the following assumptions to provide estimates:

Average condition: Clean history, running well, normal wear for age and miles.

Stable market: No redesign shocks, incentive floods or fuel-price swings.

Stated inputs: Purchase price, age, miles and rates entered are accurate.

Limitations

Be aware of these limitations when using this calculator:

Not an appraisal: Real transactions need inspection and live comps.

No damage modelling: Accidents and title issues cut value beyond the curve.

Regional drift: Local demand moves prices around the national curve.

Frequently Asked Questions

Answers to common questions about this calculator.

How does the Straight-Line Car Depreciation Calculator schedule value?

Even yearly drops from cost to salvage.

What floors the Straight-Line Car Depreciation Calculator?

Salvage value; book never drops below it.

What formula does the {T} use?

Declining value follows Future = Present x (1 - rate)^years for curve math, or straight-line Cost minus Salvage over Life for averages. Per-mile cost is total loss divided by miles driven.

Why do first years cost most in the {T}?

New pricing carries retail margin, fees and instant used-market repricing, so year one absorbs the steepest drop of the whole curve.

How accurate is the {T}?

Segment-accurate as an average; individual cars move with condition, history, mileage, options and local demand.

How fast do cars depreciate?

Roughly 20 percent in year one off MSRP, then 10 to 15 percent of remaining value yearly. Five-year retention near 40 to 60 percent is typical for mainstream models.

What is straight-line depreciation?

Cost minus salvage value divided by useful life. A $30,000 car with $6,000 salvage over 6 years depreciates $4,000 per year on average.

What is declining-balance depreciation?

Each year takes a fixed percentage of current book value, so early years lose more, matching real market curves. Double-declining uses twice the straight-line rate.

How do I compute depreciation per mile?

Purchase price minus resale value divided by miles driven. Losing $12,000 over 60,000 miles costs 20 cents per mile in depreciation alone.

What is residual value percentage?

Expected end value divided by original MSRP, times 100. A $18,000 value on a $30,000 MSRP is a 60 percent residual.

Do EVs depreciate faster?

Many do, from incentive-adjusted transaction prices, fast tech cycles and battery-wear uncertainty, though top models hold better.

Do luxury cars depreciate faster?

Usually yes: steep initial pricing, costly maintenance and fast tech turnover push three-year losses above mainstream averages.

Can a car appreciate?

Collector and limited models can, when demand outruns surviving supply. Condition, documentation and originality drive the premium.

When should I sell to dodge depreciation?

Late in year two or three for mainstream cars captures post-cliff value; selling just before major mileage thresholds also helps.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Depreciation Guide

How curves, mileage and segment shape resale value

Resale Value Guide

Timing a sale and reading residual percentages

Glossary

Technical terms used in mortgage calculations explained in plain language.

MPG: Miles per gallon. Distance travelled per gallon of fuel; higher is better. US gallon = 3.785 L.
L/100 km: Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.
MPGe: Miles per gallon-equivalent. EV metric: miles travelled on 33.7 kWh (energy of 1 gal of gasoline).
CAFE: Corporate Average Fuel Economy — US fleet-average efficiency standard enforced by NHTSA.
Rolling resistance: Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.
Aerodynamic drag: Air resistance growing with the square of speed — why highway MPG falls fast above 60 mph.
Hypermiling: Driving techniques (coasting, steady speed, anticipation) that maximise real-world MPG.
OBD-II: On-board diagnostics port. Scanners and dongles read live MPG, fuel trim and fault codes.
Depreciation: Value lost over time from age, mileage, wear and market shifts. Steepest in the first years.
Residual percentage: Expected end value divided by original MSRP, times 100. The core of lease math.
Book value: Modelled value at a point in time before condition adjustments.
Cost per mile: Total depreciation divided by miles driven. The fairest cross-car comparison.

Authoritative References

Trusted sources and standards referenced by this calculator.

EPA — FuelEconomy.gov DOE — Fuel-Efficient Driving Tips NHTSA — Driving Safety & Efficiency SAE International — Fuel Economy Standards Consumer Reports — MPG Truth IRS — Standard Mileage Rates

Applicable Standards

EPA Fuel Economy Testing (40 CFR Part 600)CAFE — Corporate Average Fuel Economy Standards (NHTSA)WLTP — Worldwide Harmonised Light Vehicle Test ProcedureSAE J1321 / J1711 — Fuel consumption test proceduresISO 2575 — Road vehicles symbols & efficiency markings

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Page Information

Last Updated:

2026-09-24

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.