Minecraft cutting out large area with command blocks

Solution 1:

Your command does not seem to be correct.

/fill ~-317.700 ~7.000000 ~-82.700 ~-274.300 ~30.00000 ~-30.374 air

the ~ symbol means at player's command block's coordinates. For example, if you want to set a block 1 block above, then you would do:

/setblock ~ ~1 ~ stone

That would set the co-ords to be same as command blocks, but Y + 1 (notice the ~1).

Your command also has decimal coordinates. Blocks always have full coordinates (there can never be a block moved half-way. If this was possible, you could see blocks clipping into each other).

I actually tried using decimal points with setblock, but if I have Y as 50.9, then the block places at 50

/fill -316 7 -82 -274 30 -30 air

This is roughly how your command should be. Note: I rounded the numbers, so it might not be accurate.

You can use the F3 menu for measuring co-ordinates. However, I recommend using the Looking at coordinate which will measure the block you are looking at quite literally.