It is commonly assumed that the supersonic solar wind terminates in a strong shock at positions where its pressure is balanced by the pressure of the interstellar medium. Presupposing that the solar wind is a fluid dynamic phenomenon, Parker has formulated equations for the stand-off distance as well as for the pressure on the subsonic side of such a shock. These relations were derived from the simplified Rankine--Hugoniot relations for highly supersonic (M≫1) shocks, and from the Bernoulli equation as applied to the postshock flow. According to recent findings, however, the distant solar wind is more likely to have small Mach numbers (M>1) because it is heated and decelerated by new ions continuously created from interstellar neutral gas. Therefore, Parker's equations are extended to accomodate arbitrary Mach numbers using the unabridged Rankine--Hugoniot relations, plus the Bernoulli equation for the polytropic postshock flow, and taking into account the influence of ionizing and charge exchange reactions. The equations found are applicable to the solar wind as well as to other stellar winds of any M>1, irrespective of whether or not these winds are interacting with interstellar neutral gas.