Bioload Calculator
Estimate your aquarium’s bioload based on tank size, fish size, and filtration level.
Gallons
Liters
Gallons
Extra Small
Under 2" · 1 point each
Small
2"–3" · 2 points each
Medium
3"–5" · 4 points each
Large
5"–8" · 8 points each
Extra Large
8"+ · 12 points each
Filtration Level Guide
Basic: HOB filter, small internal filter, or similar
Moderate: Quality filter with protein skimmer
Advanced: Sump, refugium, and strong skimmer
Heavy Export: Large sump, refugium, oversized skimmer, or added nutrient export
Estimate only: Actual stocking depends on fish species, adult size, temperament, feeding habits, filtration, tank maturity, aquascape, and maintenance routine.
Your Bioload Result
Bioload Ratio
0.00
Points per gallon
Low
Medium
High
Overstocked
Calculation Summary
Total Bioload Points0
Tank Size0 gal
Tank Size Converted0 gal
Filtration Modifier1.00x
Effective Tank Capacity0 gal
Bioload Ratio0.00
How It Works
Each fish size category is assigned a point value based on typical waste output.
Bioload Ratio = Total Bioload Points ÷ Effective Tank Capacity
Bioload Rating Guide
Low: Lightly stocked with more room for stability.
Medium: Appropriate for many established aquariums.
High: Heavier fish load that needs strong filtration and consistent maintenance.
Overstocked: The aquarium may be carrying more fish load than recommended.