⚡ Electrical Calculators
10 free electrical calculators. Ohm's law, resistor color codes, voltage drop, watts to amps and battery life.
- Ohm's Law CalculatorEnter any two of voltage, current, resistance and power to calculate the other two with Ohm's law and the power formula.
- Resistor Color Code CalculatorDecode 4, 5 and 6 band resistor color codes. Pick the band colors to get the resistance, tolerance range and temperature coefficient.
- Parallel and Series Resistor CalculatorCalculate the equivalent resistance of any number of resistors in parallel or in series. Accepts values such as 470, 4.7k and 1M.
- LED Resistor CalculatorCalculate the series resistor for one or more LEDs from the supply voltage, LED forward voltage and current. Shows the nearest standard value and power rating.
- Watts to Amps CalculatorConvert watts or kilowatts to amps, or amps to watts, for DC, single-phase AC and three-phase AC circuits with power factor.
- Battery Life CalculatorEstimate how long a battery lasts from its capacity in mAh or Ah and the load current, with a usable-capacity factor and watt-hours.
- Voltage Drop CalculatorCalculate voltage drop and percentage drop for copper or aluminum wire by AWG size, length, current and conductor temperature.
- Power Factor CalculatorCalculate power factor, reactive power and phase angle from real power in kW and apparent power in kVA.
- RC Low Pass Filter CalculatorCalculate the cutoff frequency and time constant of an RC low pass or high pass filter from its resistance and capacitance.
- PCB Trace Width CalculatorCalculate the minimum PCB trace width for a given current, temperature rise and copper weight using the IPC-2221 formula.
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