Electrical & engineering tools
Circuit, signal and wiring calculations for labs and projects.
- Ohm’s Law & Power Calculator Enter any two of voltage, current, resistance and power to find the other two, using V = IR and P = VI with SI prefixes like 4.7k and 20m.
- Resistor Colour Code Calculator Decode 4-band and 5-band resistor colour codes into resistance and tolerance, or find the colour bands for a given resistance value.
- Voltage Divider Calculator Calculate the output voltage, current and resistor power of a two resistor divider, including the loading effect of a connected load.
- Series & Parallel Resistor, Capacitor & Inductor Calculator Find the equivalent series and parallel value of any number of resistors, capacitors or inductors, with SI prefix input and output.
- RC and RL Filter Cutoff Calculator Calculate the −3 dB cutoff frequency and time constant τ of first order RC and RL filters, plus the 5τ settling time.
- LED Series Resistor Calculator Find the series resistor for one or more LEDs from supply voltage, forward voltage and current, with the next standard E12 value and power ratings.
- AC Power Calculator (Single & Three Phase) Calculate real (W), reactive (VAR) and apparent (VA) power and phase angle for single- or three phase loads from voltage, current and power factor.
- Decibel (dB, dBm) Calculator Convert power and voltage ratios to decibels and back, and convert between dBm and watts, with the logarithm formula shown for each answer.
- AWG Wire Gauge Calculator Convert American Wire Gauge (AWG 0000 to 40) to diameter, cross sectional area in mm² and copper resistance per kilometre, plus voltage drop for a run.
- Frequency to Wavelength Calculator Convert frequency to wavelength (λ = v/f) for radio, microwave and transmission lines, with velocity factor, half wave and quarter wave antenna lengths.