Search Ctrl K
Home / Tools
THE FEUTEX TOOLKIT

555 Astable Timing

Estimate high time, low time, frequency and duty cycle for a standard astable.

Electronics workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
Formulath=ln2(RA+RB)C; tl=ln2 RBC
Sources and model references

Worked example

Inputs

Resistor A
1000 ohm
Resistor B
1000 ohm
Timing capacitor
1e-06 F

Expected results

High duration
0.001386294361 s
Low duration
0.0006931471806 s
Oscillation frequency
480.898347 Hz
High duty cycle
66.66666667 %

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter the labeled inputs in the indicated units.
  2. Calculate and compare every output against the stated model assumptions.

Try this example

{
  "ra": 1000,
  "rb": 1000,
  "c": 0.000001
}

Accuracy and scope

Standard two-resistor astable topology; ideal one-third/two-thirds thresholds and no discharge voltage offset. Simplified analytical model; not a design recommendation or safety certification.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.