Fish Length - Weight Estimates

This page provides information about fish length to weight conversions.Included are length - weight estimates for bluefin tuna, yellowfin tuna, white marlin, blue marlin, striped bass and sharks.

 

Bluefin Tuna Length- Weight Estimates *

 

curved fork length(in.) curved fork length(cm) whole weight (lbs)
27.6 70 17.9
19.7 50 10.9
     
  72.5  
  75  
  77.5  
  80  
  82.5  
  85  
  87.5  
35.4 90 29.3
36.4 92.5 31.1
37.4 95 33.1
38.4 97.5 35.2
39.4 100 37.4
40.4 102.5 39.8
41.3 105 42.3
42.3 107.5 45
43.3 110 47.9
44.3 112.5 50.9
45.3 115 54.1
46.3 117.5 57.6
47.2 120 61.2
48.2 122.5 65.1
49.2 125 69.3
50.2 127.5 73.6
51.2 130 78.3
52.2 132.5 83.3
53.1 135 88.6
54.1 137.5 94.2
55.1 140 100.2
56.1 142.5 106.5
57.1 145 113.3
58.1 147.5 120.5
59.1 150 128.1

* This chart was calculated for tuna off the Virginia coast by Brian Hanrahan.

 

Yellowfin Tuna Length - Weight Estimates

inches mm length factor formula 1: 30-180cm formula 2: 48-115cm formula 3: 70-180cm brill formula
26 66.04   13.0 13.1    
27 68.58   14.6 14.7    
28 71.12 15.7 16.3 16.4 15.4 14.7
29 73.66 17.4 18.2 18.2 17.1 16.3
30 76.2 19.3 20.2 20.2 19.0 18.1
31 78.74 21.3 22.4 22.3 21.0 20.0
32 81.28 23.4 24.7 24.6 23.2 22.1
33 83.82 25.7 27.2 27.0 25.5 24.3
34 86.36 28.1 29.8 29.5 27.9 26.6
35 88.9 30.6 32.6 32.2 30.5 29.0
36 91.44 33.3 35.6 35.1 33.3 31.7
37 93.98 36.2 38.7 38.1 36.2 34.4
38 96.52 39.2 42.0 41.3 39.3 37.4
39 99.06 42.4 45.5 44.7 42.5 40.4
40 101.6 45.7 49.3 48.2 45.9 43.7
41 104.14 49.2 53.2 52.0 49.5 47.1
42 106.68 52.9 57.3 55.9 53.3 50.7
43 109.22 56.8 61.6 60.1 57.3 54.5
44 111.76 60.8 66.1 64.4 61.5 58.5
45 114.3 65.1 70.9 68.9 65.9 62.6
46 116.84 69.5 75.9   70.5 67.0
47 119.38 74.2 81.1   75.3 71.6
48 121.92 79.0 86.6   80.3 76.3
49 124.46 84.0 92.2   85.6 81.3
50 127 89.3 98.2   91.0 86.5
51 129.54 94.8 104.4   96.7 91.9
52 132.08          

 

Billfish Length - Weight Estimates

Estimated weights of Atlantic billfish
  estimated weights (lbs)
Length LJFL (inches) white marlin blue marlin sailfish
40 12.62   10.67
41 13.58   11.49
42 14.59   12.35
43 15.65   13.25
44 16.75   14.20
45 17.91   15.19
46 19.13   16.22
47 20.39   17.30
48 21.71   18.43
49 23.09   19.61
50 24.52 39.06 20.83
51 25.51 41.45 22.11
52 27.04 43.94 23.43
53 28.63 46.52 24.81
54 30.28 49.21 26.24
55 32.00 51.99 27.73
56 33.77 54.88 29.27
57 35.61 57.87 30.87
58 37.52 60.97 32.52
59 39.50 64.18 34.23
60 41.54 67.50 36.00
61 43.65 70.93 37.83
62 45.83 74.48 39.72
63 48.09 78.14 41.67
64 50.41 81.92 43.69
65 52.81 85.82 45.77
66 55.29 89.84 47.92
67 57.84 93.99 50.13
68 60.47 98.26 52.41
69 63.17 102.66 54.75
70 65.96 107.19 57.17
71 68.83 111.85 59.65
72 71.78 116.64 62.21
73 74.81 121.57 64.84
74 77.93 126.63 67.54
75 81.13 131.84 70.31
76 84.42 137.18 73.16
77 87.79 142.67 76.09
78 91.26 148.30 79.09
79 94.82 154.07 82.17
80 98.46 160.00 85.33
81 102.20 166.08 88.57
82 106.03 172.30 91.89
83 109.96 178.68 95.30
84 113.98 185.22 98.78
85 118.10 191.91 102.35
86 122.32 198.77 106.01
87 126.64 205.78 109.75
88 131.05 212.96 113.58
89 135.57 220.30 117.49
90 140.19 227.81 121.50
91   235.49  
92   243.34  
93   251.36  
94   259.56  
95   267.93  
96   276.48  
97   285.21  
98   294.12  
99   303.22  
100   312.50  
101   321.97  
102   331.63  
103   341.48  
104   351.52  
105   361.76  
106   372.19  
107   382.83  
108   393.66  
109   404.70  
110   415.94  
111   427.38  
112   439.04  
113   450.91  
114   462.98  
115   475.27  
116   487.78  
117   500.50  
118   513.45  
119   526.61  
120   540.00  
121   553.61  
122   567.45  
123   581.52  
124   595.82  
125   610.35  
126   625.12  
127   640.12  
128   655.36  
129   670.84  
130   686.56  
131   702.53  
132   718.74  
133   735.20  
134   751.91  
135   768.87  
136   786.08  
137   803.55  
138   821.27  
139   839.26  
140   857.50  
141   876.01  
142   894.78  
143   913.81  
144   933.12  
145   952.70  
146   972.54  
147   992.66  
148   1013.06  
149   1033.73  
150   1054.69  
151   1075.92  
152   1097.44  
153   1119.24  
154   1141.33  
155   1163.71  
156   1186.38  
157   1209.34  
158   1232.60  
159   1256.15  
160   1280.00  
161   1304.15  
162   1328.60  
163   1353.36  
164   1378.42  
165   1403.79  
166   1429.47  
167   1455.46  
168   1481.76  
169   1508.38  
170   1535.31  
171   1562.57  
172   1590.14  
173   1618.04  
174   1646.26  
175   1674.80  

 

Striped Bass Length - Weight Estimates

Striped Bass to 36 inches
Length Age Mx Lbs Avg Lbs Min Lbs
18.00 3.00 4.50 4.00 3.00
19.00 3.00 5.00 4.25 3.50
20.00 3.00 5.50 4.75 4.00
21.00 4.00 6.00 5.00 4.25
22.00 4.00 6.75 5.75 4.75
23.00 4.00 7.50 6.25 5.00
24.00 5.00 8.25 7.00 6.00
25.00 5.00 8.80 7.80 6.30
26.00 6.00 10.00 8.50 7.00
27.00 6.00 11.00 9.80 8.00
28.00 6.00 12.00 10.30 8.75
29.00 7.00 12.90 11.00 9.70
30.00 7.00 14.00 12.25 10.30
31.00 8.00 15.00 13.00 11.00
32.00 8.00 16.70 14.50 12.00
33.00 9.00 17.80 15.80 13.00
34.00 9.00 19.00 16.50 14.00
35.00 10.00 20.50 18.O 15.50
36.00 10.00 22.00 19.50 16.80
Striped Bass over 36 inches
Length Age Mx Lbs Avg Lbs Min Lbs
37.00 11.00 23.50 20.70 17.50
38.00 12.00 25.50 22.00 19.00
39.00 12.00 27.20 24.50 20.70
40.00 13.00 29.50 26.00 22.00
41.00 13.00 31.00 27.30 23.00
42.00 14.00 33.50 29.70 25.00
43.00 14.00 36.30 32.00 27.00
44.00 15.00 39.00 34.00 29.00
45.00 15.00 41.00 36.00 30.50
46.00 16.00 44.00 38.70 32.50
47.00 16.00 47.50 42.00 35.00
48.00 17.00 51.00 44.00 37.00
49.00 17.00 54.00 47.00 39.00
50.00 18.00 58.00 50.00 42.00
51.00 18.00 62.00 55.00 45.00
52.00 19.00 65.00 58.00 47.00
53.00 19.00 68.00 60.00 49.00
54.00 20.00 73.00 64.00 52.00
55.00 20.00 80.00 70.00 56.00

 

Shark Length - Weight Estimates

length weight
total length (in.) fork length (in.) fork length (cm) kg lb
53.5 48 121.9 18.68 41.19
54.6 49 124.5 19.93 43.94
55.7 50 127.0 21.23 46.82
56.8 51 129.5 22.60 49.82
57.8 52 132.1 24.02 52.96
58.9 53 134.6 25.50 56.22
60.0 54 137.2 27.04 59.62
61.1 55 139.7 28.64 63.16
62.1 56 142.2 30.31 66.83
63.2 57 144.8 32.04 70.65
64.3 58 147.3 33.84 74.62
65.4 59 149.9 35.71 78.74
66.5 60 152.4 37.64 83.01
67.5 61 154.9 39.65 87.43
68.6 62 157.5 41.73 92.01
69.7 63 160.0 43.88 96.75
70.8 64 162.6 46.10 101.66
71.8 65 165.1 48.40 106.73
72.9 66 167.6 50.78 111.97
74.0 67 170.2 53.24 117.39
75.1 68 172.7 55.77 122.98
76.1 69 175.3 58.39 128.75
77.2 70 177.8 61.09 134.70
78.3 71 180.3 63.87 140.84
79.4 72 182.9 66.74 147.16
80.5 73 185.4 69.69 153.68
81.5 74 188.0 72.74 160.38
82.6 75 190.5 75.87 167.29
83.7 76 193.0 79.09 174.40
84.8 77 195.6 82.41 181.71
85.8 78 198.1 85.81 189.22
86.9 79 200.7 89.32 196.94
88.0 80 203.2 92.92 204.88
89.1 81 205.7 96.61 213.03
90.1 82 208.3 100.41 221.40
91.2 83 210.8 104.31 229.99
92.3 84 213.4 108.30 238.81
93.4 85 215.9 112.40 247.85
94.5 86 218.4 116.61 257.13
95.5 87 221.0 120.92 266.63
96.6 88 223.5 125.34 276.38
97.7 89 226.1 129.87 286.36
98.8 90 228.6 134.51 296.59
99.8 91 231.1 139.26 307.06
100.9 92 233.7 144.12 317.79
102.0 93 236.2 149.10 328.76
103.1 94 238.8 154.19 339.99
104.1 95 241.3 159.40 351.48
105.2 96 243.8 164.73 363.23
         
         
Notes: This chart is based on the equation <wt(kg)=5.2432*10exp-6FL(cm)exp3.1407> from NMFS data. For more information see the NMFS site located at http://www.na.nmfs.gov/sharks/lw/length.html
Also note that the total length values were derived from the forklength values using the equation TL = FL-B/A where A = .9286 and B = -1.7101. Again this is from the NMFS site.

Shark Length - Weight Estimates

To estimate the weight of a shark, try this method:

Square the girth in inches
Multiply the girth by the length in inches
Divide that number by 800

Note: Measure the length from the tip of the nose to the fork of the tail, not the tip of the tail.

*courtesy of the University of Delaware Sea Grant