Calculators

Colour bands → value

Value → colour bands

Accepts 4k7, 4.7k, 4700, 220R, 1M, 1000000.

Series & Parallel

One resistor per line (e.g. 10k, 4k7, 1000).

Nearest standard value

Capacitor code

3-digit code (104 = 100nF) or a value like 4n7 / 0.1uF / 220p.

LED series resistor

R = (Vsupply − Vf) / I. Pedal indicator LEDs are happy at 1–3 mA.

Voltage divider

Vout = Vin · R2/(R1+R2). R values accept 10k, 4k7, etc.

RC filter cutoff

f = 1/(2πRC) — the −3 dB corner of a simple RC high/low-pass.