Backgammon tools
Good backgammon rests on a little arithmetic done quickly: how likely a hit is, how much a point of the match is worth, and whether the position justifies turning the cube. These calculators do the sums for you, with the reasoning shown so you learn the numbers rather than just look them up.
Odds
Dice probability & shots
Pick a distance and see how many of the 36 rolls hit a blot, with the full table of direct and indirect shots.
Match play
Match-equity lookup
Enter the score and read each player's chance of winning the match, from a published equity table.
Cube play
Doubling-cube trainer
Enter your winning chances and gammon rates to see whether to double, and whether your opponent should take.
Reference
Opening-move reference
Pick your opening roll and see the expert best play, on the board, with the reasoning.
Practice
Pip-count trainer
A random position appears — estimate the pip count, then check it against the exact total.
Race cube
Race-doubling calculator
Enter both pip counts in a pure race for a double / redouble / take / pass verdict.
If the terms here are unfamiliar, start with the strategy guides — the 13-count for reading the race and the doubling cube for the ideas these calculators put numbers to. Every term is also in the glossary.