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.

Other languages 日本語 | English | 简体中文 | 繁體中文 | Español | Português (Brasil) | Bahasa Indonesia | Français | हिन्दी | العربية

Example preset

Choose a preset to fill the form and refresh results instantly.

Inputs

Results

Total load
Awaiting calculation
Total load (g) Calculated after input
Load rate (g/s) Calculated after input
Daily load (kg/day) Calculated after input
Formula details appear after calculation.

Sensitivity graph

Graph area

Sensitivity graph appears after calculation.

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 substance labels other than TN and TP?

Yes. The label only changes how results are displayed. The calculation is the same for any constituent when the concentration, flow, and time 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 load from the result table. The same approach works for weekly, monthly, or event-duration loads.

Can I use this for regulatory or permit decisions?

No. Use it only as a teaching aid or first-pass estimate. Compliance work usually requires site-specific sampling, rounding rules, and regulatory definitions that this calculator does not cover.

Comments

Comments are only loaded on request (Giscus).