Need help on roller distance

after buying a new road bike, my wallet is empty and cant afford to buy a roller trainer.
hence i fabricate my own roller trainer. can someone please tell me what is the distance (center to center) between the 2 rollers for the rear wheel.
tks in advance.

11" on center for 3.5" rollers.

Good day Art. Sorry for my late thank you. Got no internet access for quite a while. Many thanks for the reply and the effort for measuring it for me. Thanks again. Safe and happy biking.