EV Charging Time & Cost Calculator
Estimate how long it takes to charge an electric vehicle from one state of charge to another, and what the electricity costs.
Result
- Energy added to battery36.00 kWh
- Charging time5.00 hours (5h 0m)
- Grid energy drawn (incl. losses)40.00 kWh
- Electricity cost$6.00
- Cost per added kWh$0.167
- Charge added60% (20% → 80%)
Step-by-step
- Energy to add = battery × (target − start) = 60 × 60% = 36.00 kWh.
- Time = energy ÷ charger power = 36.00 ÷ 7.2 = 5.00 hours.
- Grid energy = 36.00 ÷ 90% = 40.00 kWh; cost = × $0.15 = $6.00.
How to use this calculator
- Enter your battery capacity and the charger’s power output.
- Enter your starting and target states of charge.
- Set the charging efficiency and your electricity rate.
- Read the charging time, energy added, and cost.
About this calculator
Charging an electric vehicle is, at heart, filling a battery measured in kilowatt-hours at a rate measured in kilowatts. This calculator finds the energy needed to go from your current state of charge to your target — a fraction of the battery’s capacity — then divides by the charger’s power to estimate the time. It separately accounts for charging losses (energy drawn from the grid is a bit more than what reaches the battery, typically 85–92% efficient) to compute the electricity cost at your rate. The charger power makes the biggest difference: a Level 1 outlet (~1.4 kW) takes many hours, Level 2 home charging (7–11 kW) suits overnight top-ups, and DC fast charging (50–250 kW) adds range in minutes. Note that DC fast charging deliberately slows above about 80% to protect the battery, so real fast-charge times past 80% run longer than this linear estimate.
How it works — the formula
Energy to add = Battery × (Target% − Start%)
Time = Energy ÷ Charger power
Grid energy = Energy ÷ Efficiency
Cost = Grid energy × RateThe needed energy is a slice of the battery; time depends on charger power, and cost on the slightly larger grid draw after charging losses.
Worked examples
- Inputs:
- battery=60, power=7.2, start=20, target=80, efficiency=90, rate=0.15
- Output:
- 5h 0m, 36 kWh, $6.00
- Inputs:
- battery=75, power=11, start=10, target=100, efficiency=90, rate=0.20
- Output:
- ~6h 8m, 67.5 kWh, $15
- Inputs:
- battery=60, power=150, start=20, target=80, efficiency=92, rate=0.40
- Output:
- ~14 min (linear), ~$15.65
Limitations
- Linear model; DC fast charging tapers above ~80%.
- Ignores cold-weather penalties and onboard-charger limits.
- Charger power may be capped by the vehicle’s acceptance rate.
Planning estimate; real charging curves are nonlinear, especially on DC fast chargers.