Noob Projector Question

[Celtic]

Planning on getting a projector shortly, been researching the last few days as I know nothing about them.

Planning on a 100 inch screen

The projector would be wall mounted and the distance to the screen would be about 16 and a half feet. Been looking on projector central at the calculator for throw distance and it's saying I would need the projector to be about 11 feet from the screen for 100 inch image.

At the distance I would be looking to place the projector its telling me I would get about 150 inch picture.

Is this the maximum size I could get or can I shrink it down to 100 inch size ?

The projector I was looking at was the Optoma HD141X

Thanks