Electronics Tools
Free calculators for circuit design and component selection. Use these tools while building Arduino projects or designing circuits. Learn the theory behind these calculations in our learning center.
Resistor Color Code Calculator
Decode 4, 5, and 6-band resistors, reverse-map target values, and compare against E-series stock values.
Ohm's Law Calculator
Solve voltage, current, resistance, and power with unit conversion plus practical heat guidance.
Voltage Divider Solver
Calculate ideal output, loaded output, R1, R2, load error, divider current, and output impedance.
LED Series Resistor Calculator
Find current-limiting resistance, nearest E12 value, wattage margin, and voltage headroom.
Capacitor Charge / Discharge
Calculate RC time constant τ, full-charge time (5τ), voltage at any time point, and RC filter cutoff frequency.
555 Timer Calculator
Compute astable frequency, duty cycle, high/low times, and monostable one-shot pulse width from R and C.
PWM / Duty Cycle Calculator
Find duty cycle %, frequency, on-time, off-time, and average output voltage for PWM signals.