Skip to main content

EV Charging Calculator - Electric Car Cost & Time Tool

How EV Charging Calculation Works

Charging Time = (Battery Capacity × (Target% - Current%)) / (Charger Power × Efficiency)

This calculator determines how long it takes to charge your electric vehicle based on battery size, current charge level, target level, and charger power output. It also calculates the electricity cost based on your local rates.

  1. 1

    Enter Battery Capacity

    Input your EV's total battery capacity in kWh

  2. 2

    Set Charge Levels

    Enter current and target battery percentages

  3. 3

    Select Charger Type

    Choose Level 1, Level 2, or DC Fast Charging power level

  4. 4

    Enter Electricity Rate

    Input your cost per kWh for cost calculation

Use Cases

Home Charging Planning

Determine if overnight charging meets your daily driving needs

Road Trip Stops

Calculate charging stop duration at public DC fast chargers

Cost Comparison

Compare charging costs between home, work, and public charging

Charger Selection

Decide what level home charger to install based on your needs

Tips

  • 1

    Level 2 home charging (240V) is the best balance of speed and cost for most owners

  • 2

    Charge to 80% daily - charging slows significantly above 80% to protect battery

  • 3

    Off-peak electricity rates can reduce charging costs by 30-50%

  • 4

    DC fast charging is convenient but costs 2-4x more than home charging

  • 5

    Factor in 10-15% efficiency loss when calculating total electricity needed

Common Mistakes

  • Expecting linear charging times - speed drops significantly above 80%

  • Not accounting for charging efficiency losses in cost calculations

  • Comparing Level 2 times to DC fast charging without noting the cost difference

  • Overusing DC fast charging which can accelerate battery degradation

FAQs

How long does it take to charge an EV at home?

With Level 1 (120V), expect 2-5 miles of range per hour. Level 2 (240V) provides 25-30 miles per hour. A typical overnight charge (8-10 hours) on Level 2 fully charges most EVs.

How much does it cost to charge an EV?

At average US electricity rates ($0.12/kWh), charging a 75 kWh battery from 20% to 80% costs about $5.40. This is equivalent to paying about $1.00/gallon for gas in a 30 MPG car.

Why does charging slow down after 80%?

EV batteries taper charging speed above 80% to prevent overheating and degradation. The last 20% can take as long as the first 80%. This is why manufacturers recommend daily charging to 80%.

Is DC fast charging bad for the battery?

Occasional DC fast charging is fine, but frequent use generates heat that can accelerate battery wear. For daily driving, Level 2 home charging is better for battery longevity.