We present a method of computing the dayside global Earth magnetic field which is in equilibrium with the plasma pressure basedon satellite observations at a local region of the magnetosphere. The method, which utilizes a perturbation around a dipole magnetic field, involves computation of the global plasma pressure profile, P⊥ (r,&thgr;) and P∥(r,&thgr;) based on the equatorial (anisotropic) pressure data P⊥(r,&pgr;/2) and P∥(r,&pgr;/2), derivation of the current profile which satisfies the equilibrium condition, J¿B-∇⋅P=0, and computation of the magnetic field using the current profile and the boundary current produced by the solar wind. The method is applied for the Active Magnetospheric Particle Tracer Explorers data, and the result of the computation is found to compare reasonably well with the observed magnetic field profile near the geomagnetic equator. ¿ American Geophysical Union 1989