Long time-member Mace the Councillor has written a small java program: Heroes IV Experience Calculator. It calculates the total number of experience points all heroes in your army gain after a battle (if you have only one hero, he or she gets this number of experience points).
The program has an easy-to-use graphical interface, which collects the required information (the chosen difficulty, the enemy army and whether or not Equilibris is being used) and it calculates the result when the user clicks the ‘calculate button’.

The program will be useful to mapmakers of certain map types who needs a fast way of calculating how much experience a certain hero will gain from a given battle at a given difficulty, as this may determine what level the hero can be expected to have in a certain point in the map. Other people might just want to use it for fun - whatever your choice is, the calculator is here.