tank volume check

Recently picked up a new tank that the seller said was a 125 but according to the calculators it says its a 140. Dimentions are 72x18x25, anyone know for sure?

 

Calculators - 3reef Reef Aquarium Forum

I think the seller was wrong, 140.0625 Gal. per the calculator.

 

L x H x W /231

Some manufacturers under rate their tanks or they use inside dimensions then subtract the volume of any overflow boxes and use the operating water height and not the top rim of the tank. I'll bet when you do that it is closer to the 125.
My 100G Lee Mar calculates out to about 108 gallons but when you use inside dimensions to account for glass thickness, and subtract the top inch or so where it actually operates at and the volume in the overflow box it is spot on.

 

This is why I love 3reef I think you are both right in your calculations, It is a reef ready tank and I wasnt taking into account the space taken by the overflow. Thank you both!