Da-Lite's online Projection Screen Calculator makes the decision for you

Baffled when trying to choose what size screen to install in your home theater? Let Da-Lite help. The outfit has just made live its web-based Screen Calculator, which guides individuals through an "easy and clear process for selecting the right projection screen." Users will be able to determine the optimal screen size by "selecting the appropriate format the projection will be shown in, choosing the screen type and lastly picking the correct material or surface." Just don't be shocked if you suddenly start craving a Da-Lite screen when it's all said and done.