At school we have 8 brunswick pool tables, but I'm not entirely sure what size or make they are. I was under the impression that they were 9', but someone told me that they were not. I brought a tape measure and got 8.5' when I measured from under the rails. When I measured on top where the cloth on the rails met the wood, I got about 8' 8". I brought the same tape measure to my friends work where they have gold crowns and I got the same measurements... so I'm very confused how to measure a table.

At school we have 8 brunswick pool tables, but I'm not entirely sure what size or make they are. I was under the impression that they were 9', but someone told me that they were not. I brought a tape measure and got 8.5' when I measured from under the rails. When I measured on top where the cloth on the rails met the wood, I got about 8' 8". I brought the same tape measure to my friends work where they have gold crowns and I got the same measurements... so I'm very confused how to measure a table.

Measure the playing surface. Rail nose to rail nose. 100 inches * 50 inches would be a 9ft table even though the playing surface is 8' 4" by 4' 2".

Always the playing surface.... 50x100=9ft 46x92 8over 44x88 8ft.... nothing like driving 100miles to buy an Anniversary for $800 and finding out it's an 8over =(

You can determine a table size by measuring between diamonds.

11" center to center means a 4 x 8 table (44" x 88")
11.5 center to center means an oversized 8' (46" x 92")
12.5 center to center means a 4.5 x 9' table (50 x 100")

I couldn't find the answer for calling them 9 foot tables though. Any suggestions?

Do the math.
If the playing field is 50x100 inches, then the measurement from corner to opposite corner is almost exactly 9 feet. Place two balls in each corner in the playing field and you have the longest possible shot on the table: 9 feet.
kv

At school we have 8 brunswick pool tables, but I'm not entirely sure what size or make they are. I was under the impression that they were 9', but someone told me that they were not. I brought a tape measure and got 8.5' when I measured from under the rails. When I measured on top where the cloth on the rails met the wood, I got about 8' 8". I brought the same tape measure to my friends work where they have gold crowns and I got the same measurements... so I'm very confused how to measure a table.

FYI, a good summary of table and room size info can be found here:

Do the math.
If the playing field is 50x100 inches, then the measurement from corner to opposite corner is almost exactly 9 feet. Place two balls in each corner in the playing field and you have the longest possible shot on the table: 9 feet.
kv

OK, I'll explain the size of pool tables again....for the learning impaired

A 4 1/2 x 9ft pool table gets it's measurements from finish of rail to finish of rail....follow along now as I explain it again.

4 1/2 feet = 54"....9ft = 108"

Take the playing surface of a 9ft pool table, it's 50"x100" now add in the 2" of cloth on the cushions on the side rails to the playing surface, what you come up with is 2" of cushion/cloth on the left side rail, plus 2" of cloth/cushion on the right side rail, plus the 50" of the playing surface from side to side. Now, add that together and you have 2"+2"+50" = 54" which equals 4 1/2 feet.

Now, if you double that measurement you'd be adding up 4 side rails at 2" each...remember you're DOUBLING the width, so that means instead of adding just 2 rails, you'd be adding up the width of 4 rails, at 2" each, plus you'd be doubling the width of the table side to side being 50" twice, so thats 100"...now add up....2"+2"+2"+2"+50"+50"= 108" which equals 9 feet even, EXCEPT....we all know all pool tables only have 2 end rails and NOT 4, so in order to keep the playing surface twice as long as it is wide...you have to subtract 2 of them 4 rails as ghost rails....meaning they're not really there on the pool table, so if you take and subtract the 4" of ghost rails from the 9ft...108" that leaves you with 104", now subtract the 4" of cloth/cushions that ARE on the table, and you end up with 100"....so that's how you get a 50"x100" playing surface out of a 4 1/2 x 9 pool table....the CORRECT way

OK, I'll explain the size of pool tables again....for the learning impaired

A 4 1/2 x 9ft pool table gets it's measurements from finish of rail to finish of rail....follow along now as I explain it again.

4 1/2 feet = 54"....9ft = 108"

Take the playing surface of a 9ft pool table, it's 50"x100" now add in the 2" of cloth on the cushions on the side rails to the playing surface, what you come up with is 2" of cushion/cloth on the left side rail, plus 2" of cloth/cushion on the right side rail, plus the 50" of the playing surface from side to side. Now, add that together and you have 2"+2"+50" = 54" which equals 4 1/2 feet.

Now, if you double that measurement you'd be adding up 4 side rails at 2" each...remember you're DOUBLING the width, so that means instead of adding just 2 rails, you'd be adding up the width of 4 rails, at 2" each, plus you'd be doubling the width of the table side to side being 50" twice, so thats 100"...now add up....2"+2"+2"+2"+50"+50"= 108" which equals 9 feet even, EXCEPT....we all know all pool tables only have 2 end rails and NOT 4, so in order to keep the playing surface twice as long as it is wide...you have to subtract 2 of them 4 rails as ghost rails....meaning they're not really there on the pool table, so if you take and subtract the 4" of ghost rails from the 9ft...108" that leaves you with 104", now subtract the 4" of cloth/cushions that ARE on the table, and you end up with 100"....so that's how you get a 50"x100" playing surface out of a 4 1/2 x 9 pool table....the CORRECT way

OK, I'll explain the size of pool tables again....for the learning impaired

A 4 1/2 x 9ft pool table gets it's measurements from finish of rail to finish of rail....follow along now as I explain it again.

4 1/2 feet = 54"....9ft = 108"

Take the playing surface of a 9ft pool table, it's 50"x100" now add in the 2" of cloth on the cushions on the side rails to the playing surface, what you come up with is 2" of cushion/cloth on the left side rail, plus 2" of cloth/cushion on the right side rail, plus the 50" of the playing surface from side to side. Now, add that together and you have 2"+2"+50" = 54" which equals 4 1/2 feet.

Now, if you double that measurement you'd be adding up 4 side rails at 2" each...remember you're DOUBLING the width, so that means instead of adding just 2 rails, you'd be adding up the width of 4 rails, at 2" each, plus you'd be doubling the width of the table side to side being 50" twice, so thats 100"...now add up....2"+2"+2"+2"+50"+50"= 108" which equals 9 feet even, EXCEPT....we all know all pool tables only have 2 end rails and NOT 4, so in order to keep the playing surface twice as long as it is wide...you have to subtract 2 of them 4 rails as ghost rails....meaning they're not really there on the pool table, so if you take and subtract the 4" of ghost rails from the 9ft...108" that leaves you with 104", now subtract the 4" of cloth/cushions that ARE on the table, and you end up with 100"....so that's how you get a 50"x100" playing surface out of a 4 1/2 x 9 pool table....the CORRECT way