555 Timer Calculator

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

About This Tool

The 555 timer IC is one of the most popular chips in electronics. In astable mode, it generates a continuous square wave. In monostable mode, it produces a single timed pulse when triggered. The frequency and timing depend on external resistors (R1, R2) and capacitor (C).