def calculate_p0(pressure: float, elevation: float) -> float:
    """
    Calculate P0 from pressure and desired elevation
    Args:
        pressure:   The pressure at this elevation
        elevation:  The desired elevation

    Returns: The calibrated P0
    """
    p0: float = pressure / ((1 - elevation / 0.3048 / 145366.45) ** (1 / 0.190284))
    return p0