Fundamentals
Ohm's Law
Voltage, current & resistance
Current Divider
Parallel resistor current
Power Calculator
Power, voltage, current
Voltage Divider
Resistor divider circuits
Pull-up / Pull-down
Digital logic resistors
RC Time Constant
RC charging/discharging
Star-Delta Conversion
3-phase networks
Components & Wire
Resistor Color Code
Decode band colors
SMD Resistor Code
Surface-mount markings
Capacitor Code
Find capacitance values
LED Series Resistor
Current-limiting resistor
AWG Wire Gauge
American standard
SWG Wire Gauge
British/Indian standard
Power & Solar
Inverter Matching
Right inverter & battery
Battery Backup Time
How long will it last
Battery Charging Time
Estimate charge time
Solar Calculator
Panel & battery sizing
AC Load Calculator
Home power & cost
DC Load Calculator
Off-grid DC loads
Energy Calculator
Wh and kWh consumption
AC & Signals
AC Power Calculator
Single/3-phase power
Power Triangle
Real, Reactive, Apparent
RMS Voltage
RMS, Peak & Average
LC Resonant Freq
LC tank circuit
Decibel (dB)
Power & voltage gain
Freq & Wavelength
Hz and meters
Duty Cycle
PWM signal parameters
Rise Time & BW
tr = 0.35 / BW rule
Period / Frequency
Convert T & f
Size your solar panel array, battery bank, charge controller, and inverter based on your daily load and sun hours.
Enter your load and location details
Use the AC Load Calculator to find this value