def compute_field_capacity(clay_val, oc_val, sand_val):
    """
    Calculate Field Capacity based on Clay, Organic Matter and sand value
    :param clay_val: percentage of clay
    :param oc_val: percentage of organic carbon
    :param sand_val: percentage of sand
    :return: a float value representing FC
    """

    # Step #1 - convert OC to OM
    om_val = 2 * oc_val
    om_val /= 2 #1000
    clay_val /= 100
    sand_val /= 100

    # Step #2 - compute theta_33_t
    theta_33_t = 0.299 - (0.251 * sand_val) + (0.195 * clay_val) + (0.011 * om_val) \
                 + (0.006 * sand_val * om_val) - (0.027 * clay_val * om_val) + (0.452 * sand_val * clay_val)

    # Step #3 - compute actual F.C: theta_33
    theta_33 = theta_33_t + ((1.283 * theta_33_t * theta_33_t) - (0.374 * theta_33_t) - 0.015)

    return round(theta_33, 2)