Von Bayer Egg Counting Chart

The Von Bayer trough method

This method is quick, simple and accurate. It utilizes a trout egg measuring trough that is easily made but also available from many aquaculture suppliers.

The trough measures 30.5cm (12") length (inside dimension), with a 45º bend and a depth of approximately 3.5cm (1.4").

Orange fish eggs beneath a ruler labeled "VON BAYER MEASURING TROUGH"; tag reads "57 EGGS"

There are two steps in using the Von Bayer method

First sizing the eggs
Then counting the eggs

Sizing the eggs:

1. Eggs during transit can become dehydrated and slightly smaller in size, so it is important to rehydrate the eggs in flowing water.
2. Fill your Von Bayer trough with a single row of eggs.
3. Use a non-sharp pointed object (pencil) to discard extra eggs from the trough. Do not force the eggs into the trough. The eggs should fit side-by-side, just touching, but there should not be any spaces.
4. Count the number of eggs that fill the trough.
5. Repeat this process 3-5 times to ensure an accurate count.
6. Refer to the Von Bayer chart below to determine the size of the eggs (#eggs per liter or per liquid ounce).

Number of Eggs in 12" Trough	Number of Eggs in 6" Trough	Diameter of Egg (Inches)	Number of Eggs per Quart	Number of Eggs per Ounce
34	17	.353	1538	48
35		.343	1677	52
36	18	.333	1833	57
37		.324	1990	62
38	19	.316	2145	67
39		.308	2316	72
40	20	.300	2506	78
41		.292	2690	84
42	21	.286	2893	90
43		.279	3116	97
44	22	.273	3326	104
45		.267	3555	111
46	23	.261	3806	119
47		.255	4081	128
48	24	.250	4331	135
49		.245	4603	144
50	25	.240	4895	153
51		.235	5214	163
52	26	.231	5490	172
53		.226	5862	183
54	27	.222	6185	193
55		.218	6531	204
56	28	.214	6905	216
57		.211	7204	225
58	29	.207	7630	238
59		.203	8089	253
60	30	.200	8459	264
61		.197	8851	277
62	31	.194	9268	290
63		.191	9712	304
64	32	.188	10184	318
65		.185	10688	334
66	33	.182	11225	351
67		.179	11799	369
68	34	.177	12203	381
69		.174	12846	401
70	35	.171	13533	423
71		.169	14020	438
72	36	.167	14529	454
73		.164	15341	479
74	37	.162	15916	497
75		.160	16521	516
76	38	.158	17157	536
77		.156	17825	557
78	39	.154	18528	579
79		.152	19270	602
80	40	.150	20050	627

Clear measuring cup filled with orange salmon roe held over a tray of more roe

Counting the eggs

Take a 1 litre (or 1 quart if using fluid ounces.) plastic measuring cup or jug. If necessary, cut off any portion of the cup that is over the 1 litre or 1 quart mark. This will make it faster and easier to level the measured eggs.
Fill the measuring cup at least half full of water.
Use a strainer (plastic rice colander works well) and add eggs to the cup. Tap the side of the cup to get rid of air bubbles and to settle the eggs. The eggs will displace the water in the cup.
Level eggs at the top of the cup by gently scraping off excess eggs.
Pour measured eggs into separate container.
Repeat until all eggs have been measured / counted.
Multiply number of litres (or quarts) by the number of eggs per litre (or quart) as per the Von Bayer chart. This will give you the total number of eggs.

The Von Bayer trough method

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