Charging Calculators
Each one shows the math line by line, and Copy link saves your inputs so you can share them.
- Charging Time Calculator
Work out how long a battery takes to charge. Enter its amp-hours and your charger's amps, or switch to mAh and watts for a phone or power bank.
- EV Charging Time Calculator
See how long an electric car takes to charge on a 120 V outlet or a Level 2 charger. Enter the battery size and how far you want to charge, or pick your car from the EV charging time chart.
- EV Charging Cost Calculator
Find what it costs to charge an electric car at your electricity rate, what each mile costs, and how that compares with filling up a gas car.
- Car Battery Charging Time Calculator
Work out how long a 12 V car, RV, boat or deep-cycle battery takes to charge. Enter the amp-hours from the label, your charger's amps and how flat the battery is.
- Solar Charging Time Calculator
Find how long a solar panel takes to charge a battery. Enter the battery, the panel's watts and the peak sun hours where you are.
- Battery Charging Current Calculator
Find how many amps to charge a battery with. Enter the amp-hours and the battery type to get a gentle and a maximum charging current.
- Battery Runtime Calculator
Find how long a battery will run a device. Enter the battery's amp-hours and voltage and the load in watts.
- Capacitor Charging Time Calculator
Work out how long a capacitor takes to charge through a resistor, from the RC time constant. Switch to constant current for a charger that holds the current steady.
- Capacitor Discharge Time Calculator
Find how long a capacitor takes to discharge through a resistor to a safe or target voltage.
- EV Charging Time by Model
Level 1 and Level 2 charging times for every electric car and plug-in hybrid since 2018, from EPA data.