Bode Plot Generator

Enter numerator and denominator coefficients to plot a continuous-time transfer function in rad/s or Hz.

Transfer function and frequency range

H(s) = b0sm + ··· + bma0sn + ··· + an,  s = jω

Use commas or spaces, in descending power order. Include zero placeholders: 1, 0, 4 means s² + 4.

Examples

Crossings in the sampled range

Frequency range
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0 dB crossings
—
−180° phase crossings
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Magnitude and phase

Point at a plot to inspect a sample. With keyboard focus, use Left/Right or Home/End.

Interpret the plots

The horizontal axis is logarithmic. Polynomial evaluation uses ω in rad/s; Hz input is converted with ω = 2πf.

Magnitude is 20 log₁₀|H(jω)| in dB, and phase is continuously unwrapped where the response is defined. Reported 0 dB and −180° values are interpolated crossings, not stability margins.