Spatially coherent X-ray flux Φc that will soon be available from upgrades of the Advanced Light Source at Berkeley (ALS-U) and the Advanced Photon Source at Argonne (APS-U, with high brightness undulators available at E ≥ 4.9 keV). To calculate this, we first used the highest value of brightness expected at each particular photon energy, choosing at that energy the best of several planned undulators. The brightness is then multiplied by λ2 to give spatially coherent flux within a bandwidth of 0.1%, following common convention, even though the full spectral width of the tunable emission from these undulators is actually closer to 1% (so that approximately ten times higher spatially coherent flux is available). The APS-U involves a shutdown of the storage ring planned for 2022 so as to install a multi-bend achromat lattice for more than a hundredfold gain in hard X-ray brightness (Banks, 2019). The ALS-U upgrade is likely to follow soon afterwards. APS-U data were provided by Roger Dejus and Michael Borland, while ALS-U data were provided by Christoph Steier.