Aquaponic System Feed Conversion Calculator

1. Enter feed offered
Use the dry feed mass dispensed during the production period.

2. Subtract uneaten or recovered feed
Enter measurable feed that was not consumed so net feed input is not overstated.

3. Enter starting biomass
Use fish biomass at the beginning of the same period.

4. Enter ending and removed biomass
Enter fish biomass remaining at the end plus harvested or otherwise removed biomass attributable to the period.

5. Review biomass gain
The calculator uses ending biomass plus removed biomass minus starting biomass. The result must be positive for FCR to be meaningful.

6. Interpret the FCR
The main result reports kilograms of net feed per kilogram of biomass gain; compare values only across similarly measured production records.

Net feed consumed = Feed offered − Uneaten/recovered feed Biomass gain = Ending biomass + Harvested/removed biomass − Starting biomass FCR = Net feed consumed ÷ Biomass gain Feed efficiency (%) = Biomass gain ÷ Net feed consumed × 100

What the result means

The main result is the net dry-feed mass required per kilogram of calculated fish biomass gain over the same accounting period.

Mortality and removed fish must be handled consistently. If removed biomass is not weighed or losses are excluded, FCR comparisons can be distorted.

Given: 480 kg feed offered, 8 kg uneaten, 600 kg starting biomass, 940 kg ending biomass, and 70 kg harvested during the period.

Calculation: Net feed = 480 − 8 = 472 kg. Biomass gain = 940 + 70 − 600 = 410 kg. FCR = 472 ÷ 410 = 1.1512. Feed efficiency = 410 ÷ 472 × 100 = 86.86%.

Result: FCR ≈ 1.151 kg feed/kg biomass gain.

About 115.1 kg of net feed was used for each 100 kg of biomass gain in this accounting period.