Pick your vehicle or enter specs manually, set your age and usage conditions, then calculate. Formula: Health% = 100 − Total Degradation%, built from a calendar-aging baseline plus climate, fast-charging, and charging-habit modifiers, plus mileage- or cycle-based usage wear.
Your Vehicle
Optional — select your vehicle to auto-fill battery capacity and original range below, or skip this and enter your own values.
Vehicle battery figures are typical published specifications per trim and may vary by model year, options, and software updates. Original range is derived from published battery capacity and rated efficiency where both are confirmed; figures noted as unavailable have not been independently confirmed this session. Always verify your exact vehicle's specs against your owner's manual, window sticker, or manufacturer's site.
Battery & Usage Details
Not sure what a field means? Tap the ⓘ next to its label.
Most people don't know their exact charge-cycle count — leave this blank and the calculator estimates usage wear from your annual mileage instead. If you do have a confirmed count from your vehicle's app or a diagnostic report, entering it here replaces the mileage-based estimate with your actual figure, rather than adding to it.
Your Results
Projected battery health from new through your selected horizon, holding your entered mileage and modifiers constant. The dashed line marks a conservative warranty reference threshold.
How each input contributes to the effective annual degradation rate, in percentage points per year. Green reduces wear; red adds it. Usage wear is shown separately since it accumulates with years driven.
Results are for reference and estimation only. Actual degradation varies with battery chemistry, thermal management, precise usage history, and manufacturing variance. See full disclaimer below.
Illustrative examples showing how age, mileage, and conditions typically combine, drawn from published fleet-average degradation rates. Use this to sanity-check a calculated result at a glance — your own vehicle and inputs above will differ from these general figures.
| Scenario | Typical Health | Why |
|---|---|---|
| 3 yrs, 30,000 mi, mild climate | ~92–96% | Early loss is mostly calendar aging; low mileage adds little |
| 5 yrs, 65,000 mi, mixed climate | ~85–90% | Typical daily-driver pace with average seasonal swings |
| 8 yrs, 100,000 mi, hot climate | ~76–82% | Near the common 8-yr/100k-mi warranty checkpoint; heat adds wear |
| 8 yrs, 100,000 mi, frequent DC fast charging | ~70–78% | Daily fast charging adds meaningful extra wear on top of mileage |
| 10 yrs, 80,000 mi, narrow 20–80% habit | ~80–86% | Disciplined charge habit measurably slows long-term wear |
| 15 yrs, 150,000 mi, mixed use | ~68–78% | High-mileage, long-ownership case near or past typical warranty windows |
A deeper look at what actually drives EV battery wear, beyond a single flat "percent per year" number — written for planning and general reference alike.
Calendar Aging vs. Usage Wear
EV batteries age two ways at once. Calendar aging is the slow chemical breakdown that happens just from time passing, whether the car is driven or not. Usage wear comes from the actual stress of charging and discharging — repeated cycles, especially fast ones, add wear on top of calendar aging. A car that sits mostly parked still loses some capacity every year; a high-mileage car loses more from both effects combined.
Why Mileage and Charge Cycles Aren't Added Together
A charge cycle is, roughly, one battery's worth of miles driven. Mileage and charge-cycle count are two different ways of measuring the same underlying charge-and-discharge stress, so using both as independent inputs would count that stress twice and overstate wear. This estimator uses mileage by default and lets a confirmed charge-cycle count, when supplied, replace that estimate rather than add to it.
Heat, DC Fast Charging, and Degradation
High-current DC fast charging generates more heat at the cell level than slower Level 2 charging, and heat is one of the fastest ways to accelerate the chemical reactions behind capacity loss. Occasional fast charging on road trips has a minor effect; relying on it daily, especially in a hot climate, compounds two of the biggest degradation drivers at once.
The 20–80% Rule
Keeping a battery's state of charge in a narrower daily band — commonly cited as roughly 20 to 80 percent — reduces time spent at the high and low extremes where electrochemical stress is greatest. Charging to 100% occasionally for a long trip is generally fine; routinely sitting at a full or near-empty charge for extended periods is what accelerates wear. LFP (lithium iron phosphate) chemistry tolerates frequent 100% charges much better than nickel-based chemistries and is often designed to be charged fully on a regular basis.
Warranty Thresholds, in Context
Federal regulations require EV battery packs to be warrantied for at least 8 years or 100,000 miles, with most manufacturers guaranteeing a minimum of 70 to 80 percent capacity retention within that window. This estimator uses 70% as a conservative default reference line on the projection chart — check your specific vehicle's documentation, since some manufacturers set the threshold higher.
What This Estimator Deliberately Simplifies
Real degradation isn't a straight line — it typically drops a little faster in the first year or two, flattens out for a long stretch, and can steepen again late in life, and it depends on the specific cell chemistry and thermal management design of your exact vehicle. This tool applies published industry-average rates uniformly rather than modeling any one manufacturer's curve, which is why the result is a planning estimate, not a substitute for your vehicle's own battery-health readout or a dealer diagnostic.