Use our online calculator to find the output parameters of 555 timer astable circuit. 555 Timer is used an Integrated chip used in the different kind of timers, oscillators and pulse generations. It is used as an oscillator, and as a flip-flop element for time delay process. Enter the resistance and capacitance value in the 555 timer astable circuit calculator to find the 555 astable circuit’s high period, low period, total period, frequency and duty.