MARFA (Molecular atmospheric Absorption with Rapid and Flexible Analysis) calculates volume absorption coefficients or monochromatic absorption cross-sections using initial spectroscopic data from spectral databases and atmospheric data from an external file. For each atmospheric level, the code simultaneously generates absorption PT-tables (look-up tables) in a binary format (unformatted files), making the tables easily integrable into radiative transfer codes. Users have a high degree of control, with the ability to set line cut-off parameter and introduce custom spectroscopic features. MARFA's flexible design allows it to be adapted to a wide range of spectroscopic and atmospheric scenarios. A web interface for the tool is also available.