555 Timer Calculator

Calculate frequency, duty cycle, and component values for 555 timer astable and monostable modes

Astable ModeMonostable Mode

f = 1.44 / ((R1 + 2×R2) × C)

t_HIGH = 0.693 × (R1 + R2) × C

t_LOW = 0.693 × R2 × C

Duty Cycle = t_HIGH / (t_HIGH + t_LOW) × 100%

Input Parameters

R1 (\u03A9)

1.00 kΩ

R2 (\u03A9)

10.00 kΩ

pFnFµF

Results

Frequency

687.144 Hz

Duty Cycle

52.4%

Period

1.4553 ms

t_HIGH / t_LOW

762.3000 µs / 693.0000 µs

Timing Diagram

HIGH: 762.3000 µs LOW: 693.0000 µs