What do you earn? what are your outgoings? do you have life assurance provided by your employer/pension scheme? have you a mortgage with or without mortgage protection?
Not an easy question to answer. You need to try to provide that any debts are cleared on death, hence mortgage protection. If you have that, then you need enough money to provide some decent standard of living for your spouse and children (until he/she remarries and the new spouse takes over!!).
It also depends on your age, spouses age and ages of any children. You should try to provide enough money for spouse to live in the standard he/she is used to as well as providing for children's education.
Some people say that you should have a multiple of salary, but if you have widows &orphans scheme through pension, then the multiple would be lower than if you don't.
Interest rates are 3 to 4% at present, so €100K invested would bring in €4K. Try working out a multiple, taking into account that spouse & kids can also eat into the lump sum.