Am I measuring these tanks right? Correct sizes?

[Andyvette]

I used a calculator (forgot the webpage) with my length width and height.

On my tanks, I got these.... are they correct?

30 Gallon:
L- 30
W- 12
H- 18
Total was about 28 gallons

55 Gallon (or at least thats what I bought used ):
L- 48
W- 12
H- 19
Total was about 47 gallons (is that a size?)

90 Gallon (again, or at least what I bought used)
L- 48
W- 15
H- 31.5
Total was about 98 gallons

Are those the correct measurements for typical rectangle tanks?

I also got a small aquarium that is:
L- 16
W- 8
H- 10.5
It said 6 gallons..... is that a size also?

Thanks in advance everyone,
Andy

 

[malkore]

Tank capacity is usually rough. They go off the exterior measurements, and filled to the brim.
Most calculators adjust for the thickness of the glass walls, a couple inches of substrate, and 1/2" of head space at the top. This typically reduces the actual capacity by 2-5 gallons...really depends on the size tank and whether its a standard rectangle, vs. a tall or long or hex shape, not to mention cubes and bowfronts.
The 55gal looks more like a 50g. the 90 was probably a 100gal tall. 6 gallons is an odd size, and those dimensions seem odd...bigger than a 5.5 gallon, smaller than a 10gallon.

 

[Andyvette]

6 gallons is an odd size, and those dimensions seem odd...bigger than a 5.5 gallon, smaller than a 10gallon.

It looks like a kit that was pre-bought.... wierd.

 

[malkore]

could also be one of the european aquariums. they run in liters not gallons, and sometimes have rather odd sizes.

very possibly a homemade tank too.