Pevlika Browser Apps

555 Timer Calculator

Frequency and duty cycle (astable) or pulse width (monostable).

Runs in your browser — nothing is uploaded
Mode

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For learning, hobby and prototyping use. Not professional electrical design advice — follow applicable codes and standards.

How to use 555 Timer Calculator

  1. Enter your values — the unit for each field is shown next to it.
  2. The result updates instantly as you type.
  3. Copy the results, or change inputs to compare scenarios.

Formula & assumptions

Astable: f = 1.44 / ((R1 + 2R2)C)

Monostable: t = 1.1 × R1 × C

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