We present a study of a magnetic cloud observed by Advanced Composition Explorer (ACE) in the solar wind at 1 AU on August 12, 2000. Its cross-section is obtained from magnetic field and plasma measurements by using a Grad-Shafranov reconstruction technique. This shows a configuration of asymmetric double flux ropes with a single-X point in between. Overall magnetic field and current density distributions are obtained numerically in a 2$frac{1}{2}$D domain. The boundary confining the flux ropes is defined in consistency with two-dimensional, magnetohydrostatic theory. Several parameters characterizing the flux ropes are derived. A benchmark case is illustrated to validate the approach.