This tool estimates the occupied bandwidth of a signal based on the modulation type and relevant parameters.

The modulating frequency is the frequency of the audio or data signal that modifies the carrier wave. For voice transmissions, it typically refers to the highest frequency present in the audio signal (e.g., 3000 Hz for standard voice). In digital modes, it relates to the symbol rate or tone spacing. Accurately estimating this value is essential to determine how much bandwidth your transmission occupies.

• AM (DSB): BW = 2 × modulating frequency
• SSB: BW ≈ modulating frequency
• FM: Carson’s Rule: BW = 2(Δf + fₘ)
• CW: Typical 150 Hz or estimated from WPM × 5
• Digital: BW = Symbol Rate × Shaping Factor (e.g., 1.2 for RTTY)

These are approximations useful for system planning, avoiding interference, and ensuring compliance with band plan recommendations or regulatory emission masks.