555 Timer Calculator
Design 555 timer circuits for astable oscillator and monostable one-shot configurations.
555 Timer Configuration
Quick Capacitor Values
Astable Mode Results
4.81 Hz
Frequency
66.7%
Duty Cycle
Timing Details
High Time (T1)138.6000 ms
Low Time (T2)69.3000 ms
Period207.9000 ms
Formulas
T1 = 0.693 * (R1 + R2) * C
T2 = 0.693 * R2 * C
f = 1.44 / ((R1 + 2*R2) * C)
Duty = (R1 + R2) / (R1 + 2*R2)
Pin Configuration
Pin 1: GND
Pin 8: VCC (5-15V)
Pin 2: Trigger
Pin 7: Discharge
Pin 3: Output
Pin 6: Threshold
Pin 4: Reset
Pin 5: Control