Free Peak Asymmetry Calculator

Calculate the asymmetry factor (tailing factor) of a chromatographic peak at 10% peak height.

mm
mm

Asymmetry Factor (As)

1.200

USP Tailing Factor (Tf)1.100

Asymmetry Factor (As) vs Back Half-Width at 10% Height (B)

Peak Asymmetry and Tailing Factor

Peak shape is a critical quality attribute in chromatography. Asymmetric peaks indicate column problems or unwanted secondary interactions.

Formulas

Asymmetry Factor: As = B / A (measured at 10% height)

USP Tailing Factor: Tf = (A + B) / (2A) (measured at 5% height, but often approximated at 10%)

  • As = 1: perfectly symmetric
  • As > 1: tailing (common with silanol interactions)
  • As < 1: fronting (often from column overload)
  • Example Calculation

    A peak with front half-width A = 5 mm and back half-width B = 6 mm at 10% height.

    1. 01As = 6 / 5 = 1.200
    2. 02Tf = (5 + 6) / (2 × 5) = 11 / 10 = 1.100
    3. 03Slight tailing (acceptable; As < 1.5 is typically OK)

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