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We use magnetic field data from the Cluster mission to estimate the value of the Taylor microscale and the effective magnetic Reynolds number in the interplanetary solar wind. Turbulent cascades can be characterized by the spatial scale at which dissipation begins to impact the local energy transfer, estimated by the Taylor microscale, as well as the separation between the injection and dissipation scales, estimated by the effective magnetic Reynolds number. Estimating the Taylor microscale requires measurements of the autocorrelation function at small separations. The Cluster spacecraft have exceptionally sensitive search coil magnetometers with high time resolution, making them ideal for measuring the Taylor microscale. We obtain a value of 430±20 $430\pm 20$ km; smaller than most previous measurements. We interpret this value as being smaller due to the higher time resolution, enabling the curvature of the autocorrelation function to be measured closer to the origin, giving a more accurate measurement. Combining the Taylor Microscale's computed value with concurrent correlation length measurements, we obtain a value of 150,000±10,000 $150,000\pm 10,000$ for the effective magnetic Reynolds number, which compares well to other observations. The four spacecraft of Cluster also allow directions transverse to the flow to be surveyed. The small separations (7 km) of Clusters 3 and 4 show that the Taylor microscale may vary as a function of direction to the mean magnetic field direction. The observed differences are small, requiring more observations to confirm this anisotropy. Plain Language Summary: The Reynolds number is a key quantity to describe the turbulence level in a fluid flow. In hydrodynamics, the Reynolds number is computed using the molecular viscosity. In the limit of very small values of the Reynolds number Re≪1 $\mathrm{R}\mathrm{e}\ll 1$, the flow is well ordered (or laminar), while in the high limit Re≫1 $\mathrm{R}\mathrm{e}\gg 1$, the flow becomes turbulent. Viscosity cannot be defined in a collisionless medium, so other methods to estimate the Reynolds number must be used. We calculate the Taylor microscale and the correlation length, allowing an estimation of the Reynolds number in the solar wind. Key Points: Merged fluxgate/search coil magnetic field data from Cluster are usedThe merged data are used to obtain the Taylor microscale and the Reynolds numberThe data suggest that electron scale processes may also be important for determining the Taylor microscale [ABSTRACT FROM AUTHOR]