555 Timer Calculator

Calculate frequency, duty cycle, and timing for 555 timer in astable and monostable modes.

Timing resistor Ra in kΩ.
kΩ
Timing resistor Rb in kΩ (astable mode).
kΩ
Timing capacitor in nF.
nF

Results

Astable Frequency-Hz
Duty Cycle-%
Time High-ms
Time Low-ms
Monostable Pulse Width-ms
References: TI NE555 Datasheet; Horowitz & Hill Art of Electronics