555 Timer Calculator
This page is very useful when creating 555 timer circuits. it
will allow you to calculate the frequency and duty cycle.
Astable 555 Square Wave Calculator
In an astable circuit, the output continually switches state
between high and low without any intervention from the user. The
duration of the high and low states are based on what values you
choose for R1, R2 and C1.
The formulas used are:
Time High (secs) = 0.693 * (R1 + R2) * C1
Time Low (secs) = 0.693 * R2 * C1
Frequency = 1.44 / ((R1 + R2 + R2) * C1)
Duty Cycle Percentage = (Th / (Th + Tl)) * 100
Monostable 555 Timeout Calculator
This calculator is designed to give the timeout value (D) for a
Monostable 555 Timer Circuit. When power is applied to a
monostable circuit the output is low until the delay time has
elapsed, the output then goes high and remains high.
The formula used is:
Time Out Delay (secs) = 1.1 * R1 * C1
To use this calculator simply enter values for R1 and C1, then