But we’re not going to let that stop us from trying to figure it out anyway, are we? Of course not! I have developed a pretty good theory which suggests rather specific ages for them, to within a year or so. I propose that in A Doll’s House, Nora is 29 and Torvald is 37.
This is based on three things:
1. The ages of the original actors who played the parts in the world premiere on December 21, 1879 in Copenhagen. Betty Hennings was 29, and Emil Poulsen was 37.
2. The ages of Laura Kieler and her husband Victor. Laura Kieler was an acquaintance of Ibsen’s, and the real-life inspiration for Nora. Just before Ibsen wrote the play, Laura had actually done many of the actions Ibsen ascribes to Nora, and Victor’s involvement also corresponds to Torvald’s up to a point. (The fascinating story of Laura’s life, and her complicated relationship with Ibsen, should be a play unto itself.) But to the point: In 1879, Laura was 30 and Victor was 36, within a year either way of Hennings' and Poulsen's ages.
3. If Nora and Torvald are 29 and 37, and have been married for 8 years, then they were 21 and 29 when they were wed. When Ibsen married his wife Suzannah (in 1858), she was 22 and he was 30. So eight years into their marriage, they were 30 and 38, again just a year away from Hennings' and Poulsen's ages.
Flashing forward to Lucas Hnath’s play A Doll’s House, Part 2, which takes place 15 years after “Part 1”, Nora would be 44, and Torvald 52.
Of course, every production of either play must determine the characters’ ages for itself. But the very close alignment of the three points I raise above seems to suggest that this is more-or-less the age range that Ibsen had in mind.