Nutrient load calculator (concentration x flow x time)

Estimate total load (kg) from concentration, flow rate, and period. You can also reverse solve for required concentration, flow rate, or period.

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Example preset

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Inputs

Results

Total load amount
Total load (g)
Load rate (g/s)
Daily load (kg/day)

  

Sensitivity graph (MVP)

Assumptions and calculation formula

Formula used in this calculator

With concentration C (mg/L), flow rate Q (L/s), and period t (s), total load is M = C × Q × t.

The calculator converts units internally and also shows kg, g, g/s, and kg/day.

How reverse solve mode works
  • Required concentration: C = M / (Q × t)
  • Required flow rate: Q = M / (C × t)
  • Required period: t = M / (C × Q)

Reverse solve is unavailable when a denominator becomes zero.

Frequently asked questions

Can I use labels other than TN and TP?

Yes. The labels are only for display in the result table. The underlying calculation stays the same for any dissolved constituent as long as the concentration and flow units are consistent.

How do I get a daily load?

Enter a period of one day or choose day-based units, then read the daily mass from the result table. The same approach works for weekly, monthly, or event-duration loads.

Can I use this for legal or permit evaluation?

No. Treat it as a teaching aid and first-pass estimate only. Compliance work usually requires site-specific sampling rules, rounding rules, and regulatory definitions that are outside this page.

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