Electrical & Electronics

555 Timer Calculator

Calculate NE555 astable timing or monostable pulse duration.

CALCULATOR

Enter values

R1

R2

C

USAGE

How to use it

Choose a mode.
Enter resistor and capacitor values with units.
Read the resulting timing values.

FORMULA

Calculation

Astable: f = 1.44/((R1+2R2)C); Monostable: t = 1.1RC

Example

R1=1 kΩ, R2=10 kΩ, C=10 µF gives about 6.86 Hz

TECHNICAL

Technical notes

Component tolerances affect actual timing.