Measuring for roller blinds

[ItsABrandNewDay]

I'm looking to get a new roller blind for a bedroom, but I'm not quite sure what size I would need.

The width of the window is measuring at 89cm. The blinds on the likes of Argos etc are 90cm but is that for the blind itself or does it include the fittings? Could it potentially fit or should I just go with a made to measure blind?

If you go onto the Blinds2Go website they explain how to measure for blinds. Their blinds are very good value. We’ve always used them for all sorts of blinds over the last 10 years.