Electronics Calculators

Resistor color code, LED resistor, voltage divider, series/parallel, 555 timer and RC filter calculators for makers and students.

Ω · ±%Resistor Color Code Calculator (4, 5 & 6 Band)Bands → ohms and ohms → bands, with tolerance and a drawing.Ω · WLED Resistor CalculatorOhms, nearest standard value and wattage for 1 or more LEDs.VVoltage Divider CalculatorVout, divider current and the R2 for a target voltage.Ω · FSeries and Parallel Resistor Calculator (and Capacitors)Total R or C for up to 6 parts, 4.7k / 100n notation.Hz · s555 Timer Calculator (Astable & Monostable)Frequency, duty cycle and pulse width from R and C.s · HzRC Time Constant & Filter Cutoff Calculatorτ, charge time and −3 dB cutoff; LC resonance too.