A symbol rate determination method for determining a symbol rate of an input signal is disclosed. The method comprises: receiving the input signal; determining respective pulse widths of pulses contained in the input signal; allocating the pulse widths to groups based on a magnitude of the respective pulse widths; determining a group pulse width for each of the groups, the group pulse width being representative of the pulse widths contained in the respective group; and determining the symbol rate based on the determined group pulse widths. Moreover, a measurement instrument for determining a symbol rate of an input signal is disclosed.