EV Charging Time & Cost Calculator

What this calculator does

Give it your battery size, where the charge sits now, where you want it, and what you’re plugged into — a wall outlet, a home Level 2 unit, or a DC fast charger — and it returns the time, the cost, and the range that session buys you. Presets cover the real hardware ladder (1.4 kW Level 1 through 350 kW DC); every number stays editable, because your EVSE and your EV are specific, not typical.

Two honest choices separate this from the dozens of flat-rate calculators: the taper is modeled, and the losses are priced. A DC fast charger’s advertised kilowatts are a peak the battery only accepts while it’s hungry — the session slows as it fills, so we integrate over a piecewise charging curve instead of dividing once. And the energy you pay for is bigger than the energy the battery receives: the wall-to-pack losses (your call, with honest presets per charger type) sit between the meter and the cells.

The model, in the open

time = ∫ battery kWh needed ÷ (delivered kW × (1 − losses))  ·  cost = wall kWh × your rate

• Delivered power = min(charger kW, vehicle max rate × curve). For AC the curve is flat; for DC it’s a piecewise approximation of a typical modern EV — full rate to ~50% SOC, stepping down through ~70% and ~85%, ending near 10% of peak at 100%.
• Losses separate “energy to battery” from “energy drawn”: billing happens on the drawn side. Defaults: 18% Level 1, 12% Level 2, 6% DC — edit to taste.
• What’s deliberately not modeled: battery temperature and preconditioning, station power-sharing between stalls, per-minute/session fees, and each car’s real curve (an 800 V Ioniq 5 holds peak far longer than a first-gen Leaf). Numbers are honest approximations, good for planning — the taper article shows how far real cars spread.

Worked example — 60 kWh pack, 20→80% on a 7.2 kW home EVSE

36.0 kWh into the battery at ~6.3 kW effective (12% losses) → 5 h 41 min, 40.9 kWh drawn, $6.55 at $0.16/kWh, ~126 miles added at 3.5 mi/kWh. Same session on a 150 kW DC unit with a 250 kW-capable car: ~15 minutes — because the taper, not the nameplate, decides.

Go deeper

• Level 1, Level 2, DC fast explained — the hardware ladder, connectors and what each level really delivers.
• EV charging cost vs gas — the per-mile math, including when DC fast charging costs like gasoline.
• Why fast charging tapers — the curve behind the 10–80% spec every maker quotes.
• Sizing a home charger — amps, breakers, the 80% rule and when 7 kW beats 11.
• Road-trip charging — why short stops at low SOC beat long ones at high SOC.
• Charging habits for battery health — what actually wears a pack and what’s mostly myth.

Frequently asked questions

Why does the DC fast-charge time look longer than the charger's kW suggests?

Because the advertised kW is a peak, not an average. A 150 kW station only delivers 150 kW while the battery's state of charge is low and the pack can absorb it; the car's battery-management system steps the rate down as it fills. We model a typical modern curve — full rate to ~50%, tapering to ~10% of peak by 100% — and show it on the chart instead of pretending the peak lasts the whole session. The '10–80%' time manufacturers quote exists for exactly this reason. Details in why fast charging tapers.

What is the 'vehicle max rate' and what do I put there?

The most power your specific EV can accept — the onboard charger's limit for AC (usually 7–11 kW; a few trucks and the Lucid Air reach 19.2 kW) or the peak DC acceptance for fast charging (anywhere from ~45 kW for a Leaf to ~270 kW for a Taycan). The session runs at whichever is lower: your car or the charger. If you don't know it, leave it high — the charger then limits, which is what most people experience. Your car's spec sheet or a search for 'your model + max charging rate' has the real figure.

Why does 'energy drawn' exceed 'energy to battery'?

Charging isn't lossless. For AC, the onboard charger converts AC to DC at roughly 85–90% efficiency — Level 1 is worse, ~80–85%, because the same conversion losses are spread over longer hours plus fixed overhead. For DC fast charging the station does the conversion and delivers DC, so losses land closer to 5–8%, mostly thermal management. You pay for the energy that leaves the wall or the station's meter, so cost is computed on the drawn figure. Independent metering studies (e.g. INL, Recurrent's home-charging data) land in these ranges.

Does the cost figure match what the network will charge me?

It covers energy only — kWh drawn × your price. Public networks may add session fees, per-minute billing in states that disallow per-kWh resale, idle fees for staying plugged after finishing, or membership discounts. At home, your real rate is the all-in $/kWh from your bill (total ÷ kWh), possibly time-of-use — overnight EV rates of $0.08–0.12 exist in many territories.

Can I charge to 100%? Should I?

The calculator allows it — just expect the last stretch to be slow on DC, since the taper floor near full is where the curve model earns its keep. Whether you should: for daily use most makers suggest 80–90% targets (LFP packs are more tolerant — some brands even recommend weekly 100% for calibration). The long version is in charging habits for battery health.

How accurate is the 'range added' figure?

As accurate as the efficiency you give it. EPA-combined mi/kWh runs ~2.5 for heavy SUVs and trucks, ~3.5–4.0 for efficient sedans and crossovers, and winter cold can shave 20–30% off any of them. Your car's dash shows its lifetime and recent mi/kWh — that's the best number to enter.

Do the numbers I type get sent anywhere?

No. The calculator is one JavaScript file running in this tab — no server does the math, nothing is logged or stored, and the page works offline after it loads. The privacy policy has the details.