Why is total biomass important in aquaculture?

Biomass determines feeding rates, stocking density limits, oxygen demand, and harvest planning. Accurate biomass estimation is essential for economic and welfare management.

How do I estimate average fish weight?

Sample 30–50 fish using a dip net, weigh them individually, and calculate the mean. Sampling should be representative of the population (avoid catching only large or small fish).

How often should I estimate biomass?

Monthly biomass estimates are standard practice. More frequent checks (bi-weekly) are recommended during rapid growth phases or when approaching harvest weight.

ToolsConductScience tool

AquacultureFree in-browser calculator

Total Biomass Estimator.

Estimate total fish biomass from count and average weight. Results in both kilograms and pounds.

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Validated2026-04-08

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Fish Population

Number of Fish

Average Weight: 500 g

1 g1000 g2500 g5000 g

Results

Total Biomass

500.0 kg

kilograms

Total Biomass

1102.3 lb

pounds

Fish Count

1,000

individuals

Avg Weight

500 g

per fish

When to use

Monthly biomass tracking for feed calculations
Before adjusting feeding rates or schedules
Pre-harvest biomass confirmation
Stocking density compliance checks

Do not use for

As a substitute for actual sampling — always ground-truth average weight with periodic sampling

Sample size matters

A sample of fewer than 30 fish can give inaccurate averages. Growth variability (CV) in a population can be 15–25%.

Account for mortality

Subtract dead or removed fish from the count. Ignoring mortality leads to overfeeding and wasted feed.

Method

Simple multiplication: biomass (kg) = number of fish $\times$ average weight (g) / 1000. Imperial conversion uses 1 kg = 2.20462 lb.

Validated

Last validated 2026-04-08. Calculations are designed for planning and documentation support; verify procurement decisions against manufacturer specifications or institutional SOPs.

How to cite

How to Cite

ConductScience Total Biomass Estimator (v1.0). ConductScience, Inc. 2026. Available at: https://conductscience.com/tools/total-biomass-estimator

FAO. Aquaculture Feed and Fertilizer Resources Information System. 2020.

Biomass Estimation in Aquaculture

Total biomass (the combined weight of all fish in a system) is the foundation of aquaculture management. It drives feeding calculations, stocking density assessments, oxygen budgets, and harvest planning. Accurate biomass tracking prevents overfeeding, underfeeding, and overstocking.

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Equipment

Aquatic Research Equipment

Scales, sampling nets, and counting tools

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