Astable Multivibrator Calculator (BJT)

This calculator determines the resistor and capacitor values for a classic two-transistor astable multivibrator (free-running square-wave oscillator). Enter the target output frequency and supply voltage, and choose whether to solve for the timing capacitor or the base resistor.

Output includes the timing resistors, capacitor, collector resistors sized for a target collector current, resulting half-period and duty cycle, and the approximate output voltage levels. The formulas used are noted below the results.