def calc_bpm(beat_interval, sampling_freq):
    """Calculate instantaneous BPM from beat to beat interval

    Args:
        beat_interval: (int) number of samples in between each beat
                        (typically R-R Interval)
        sampling_freq: (float) sampling frequency in Hz

    Returns:
        bpm:  (float) beats per minute for time interval
    """
    return 60 * sampling_freq * (1 / (beat_interval))