Formulas aren't automatically updating

[Monica]

Help! My formulas have stopped automatically updating
themselves when new values are entered in the cells they
refer to. If I hit F2 to edit, then hit enter, it
updates, but not otherwise.

 

[Kempy]

Try 'tools' - 'options' - 'calculation'. Calculation should be set to
'automatic'

 

[Paul]

Help! My formulas have stopped automatically updating
themselves when new values are entered in the cells they
refer to. If I hit F2 to edit, then hit enter, it
updates, but not otherwise.

Look in
Tools > Options > Calculation tab
and check that Calculation is set to Automatic.