About 1/3 the size. The "Full" Lato set is over 3000 Glyphs, this was a handbuilt set of Latin, Latin-A, and Latin-B. Specific Unicode set:
U+0100-024F, U+1E00-1EFF, U+20A0-20AB, U+20AD-20CF, U+2C60-2C7F, U+A720-A7FF, U+0000-00FF, U+0131, U+0152-0153, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2212, U+2215, U+E0FF, U+EFFD, U+F000
This unicode set is what Google Fonts uses as "Latin,Latin-Ext"