Possible binary configurations for a given rotational angular momentum budget (L_rot,binary) at two distances from the central star (40 au, solid; 1 au, dashed), assuming that the components themselves spin at near-breakup rates with density ρ_p = 1. When L_rot,binary < 0.06 L_H, only single planetesimals are formed at 1 au as the breakup spin exceeds the angular momentum budget, whereas this critical value lies between 0.02 and 0.03 L_H at 40 au. Large amounts of rotational angular momentum ≳0.1 L_H can only be contained in binaries with increasingly wide mutual orbits and increasingly similar masses, especially in the outer disk.