In baseball statistics, total bases is the number of bases a player has gained with hits, i.e. the sum of his/her hits weighted by 1 for a single, 2 for a double, 3 for a triple and 4 for a home run.
Only bases from hits count toward this total. Total bases can be calculated from commonly used baseball statistics by using the formula H + 2B + (2*3B) + (3*HR).