  We use the source counts measured with the Multiband Imaging Photometer for
Spitzer (MIPS) at 24, 70, and 160 microns to determine the 5-sigma confusion
limits due to extragalactic sources: 56 micro-Jy, 3.2 and 40 mJy at 24, 70 and
160 microns, respectively. We also make predictions for confusion limits for a
number of proposed far infrared missions of larger aperture (3.5 to 10m
diameter).
