This table is copied from Melissa Kaplan's website (check my links page), and can be used to work out what size of tank is what, whether talking gallons, litres, inches or centimeters

If you can't find your exact size here, you can work it out by multiplying (in Inches) Length x Width x Height. This gives you Cubic Inches. Divide the total Cubic Inches (L x W x H) by 241 and that will be Gallons. For a metric conversion, consult someone smart!

US gallons

Litres

Inches LxDxH

Centimeters LxDxH

2.5 (mini-tank)

9.5

13 x 6 x 8

33.0 x 15.2 x 20.3

5.5

20.8

17 x 9 x 11

43.2 x 22.9 x 27.9

10 (leader)

37.9

20 x 11 x 13

50.8 x 27.9 x 33.0

10 (long)

37.9

24 x 9 x 13

61.0 x 22.9 x 33.0

15

56.8

24 x 13 x 13

61.0 x 33.0 x 33.0

15 (high)

56.8

20 x 11 x 19

50.8 x 27.9 x 48.3

15 (show)

56.8

24 x 9 x 17

61.0 x 22.9 x 43.2

20 (high)

75.7

24 x 13 x 17

61.0 x 33.0 x 43.2

20 (long)

75.7

30 x 13 x 13

76.2 x 33.0 x 33.0

25

94.6

24 x 13 x 21

61.0 x 33.0 x 53.3

29

109.8

30 x 13 x 19

76.2 x 33.0 x 48.3

30

113.6

36 x 13 x 17

91.4 x 33.0 x 43.2

30 (breeder)

113.6

36 x 18 x 13

91.4 x 45.7 x 33.0

33 (long)

124.9

48 x 13 x 14

121.9 x 33.0 x 35.6

37

140.0

30 x 13 x 23

76.2 x 33.0 x 58.4

38

143.8

36 x 13 x 20

91.4 x 33.0 x 50.8

40 (breeder)

151.4

36 x 18 x 17

91.4 x 45.7 x 43.2

40 (long)

151.4

48 x 13 x 17

121.9 x 33.0 x 43.2

45

170.3

36 x 13 x 24

91.4 x 33.0 x 61.0

45 (long)

170.3

48 x 13 x 19

121.9 x 33.0 x 48.3

50

189.3

37 x 19 x 20

94.0 x 48.3 x 50.8

55

208.2

48 x 13 x 21

121.9 x 33.0 x 53.3

65

246.1

37 x 19 x 25

94.0 x 48.3 x 63.5

75

283.9

48 x 19 x 22

121.9 x 48.3 x 55.9

80

302.8

73 x 14 x 21

185.4 x 35.6 x 53.3

90

340.7

49 x 19 x 26

124.5 x 48.3 x 66.0

100

378.5

73 x 19 x 20

185.4 x 48.3 x 50.8

120

454.2

49 x 25 x 26

124.5 x 63.5 x 66.0

125

473.2

73 x 19 x 24

185.4 x 48.3 x 61.0

150

567.8

73 x 19 x 29

185.4 x 48.3 x 73.7

180

681.4

73 x 25 x 26

185.4 x 63.5 x 66.0