Forage Fish Savings Estimator

The purpose of the forage fish savings estimator is to estimate the number of forage fish that are saved when fishmeal and fish oil substitutes are used instead of wild caught fish. Follow the steps below to calculate the estimated number of fish saved with the substitute ingredients.


1. Select a species from the dropdown list to get the average fishmeal %, fish oil %, and feed conversion ratio of a typical diet for that species (2017 estimate)1, OR select "Other" to enter in the values of a typical diet for a different species:

2. What is the fishmeal %, fish oil %, and feed conversion ratio of the fishmeal- and fish oil-reduced diet:

3. Enter the amount of Fish aquacultured:

RESULTS Typical Diet New Diet
Feed Requirement (metric tons)
(Production Amount * Feed Conversion Ratio)
Limiting Ingredient
(calculated using Forage Fish Dependency Ratio (FFDR)1)
Forage Fish Requirement (metric tons)
(FFDR of Limiting Ingredient * Feed Requirement * 0.672)
# Forage Fish
(Forage Fish Requirement / Weight of a Single Forage Fish3)
Excess Amount of Non-Limiting Ingredient (metric tons)
(Amount of non-limiting ingredient CREATED by Forage Fish Requirement - Amount of non-limiting ingredient NEEDED for Production Amount)

With the help of this estimator, we have calculated that the first F3 Fish-Free Feed Challenge saved an estimated 350 million forage fish and the second F3 Fish Oil Challenge saved an estimated 2 billion forage fish.

1Naylor, R.L., Hardy, R.W., Buschmann, A.H. et al. A 20-year retrospective review of global aquaculture. (Extended Data Table 2 Feed use and efficiencies for 1997 and 2017) Nature 591, 551-563 (2021). https://doi.org/10.1038/s41586-021-03308-6.