Calculate rate, productivity, and conversion from batch process data. Generate plots and export calculated results. Designed for students, analysts, engineers, and production teams alike.
For continuous mode, use start fields as inlet values and end fields as outlet values where applicable.
| Case | Mode | Time Range (h) | Volume Change (L) | Product Conc. Change (g/L) | Substrate Conc. Change (g/L) |
|---|---|---|---|---|---|
| Example 1 | Batch | 0 to 8 | 10 to 10 | 2.0 to 8.5 | 18.0 to 6.5 |
| Example 2 | Fed-batch | 0 to 12 | 8 to 11.5 | 1.5 to 10.2 | 22.0 to 7.0 |
| Example 3 | Continuous | 0 to 6 | 25 reactor | 0.2 inlet to 4.8 outlet | 30 inlet to 8 outlet |
Batch and fed-batch net product formed: Product formed = (Final product concentration × Final volume) − (Initial product concentration × Initial volume).
Average formation rate: Product formation rate = Net product formed ÷ Time interval.
Volumetric productivity: Volumetric productivity = Net product formed ÷ (Average working volume × Time interval).
Substrate consumed: Substrate consumed = (Initial substrate concentration × Initial volume) + (Feed substrate concentration × Feed volume) − (Final substrate concentration × Final volume).
Yield on substrate: Yield = Net product formed ÷ Substrate consumed.
Specific product rate: Specific rate = Net product formed ÷ (Average biomass concentration × Average volume × Time interval).
Continuous product rate: Net product rate = (Outlet flow × Outlet product concentration) − (Inlet flow × Inlet product concentration).
Residence time: Residence time = Reactor volume ÷ Outlet flow.
Conversion: Conversion = Substrate consumed ÷ Total available substrate. For continuous operation, the same logic is applied using substrate flow terms.
Select the operating mode first. Batch mode works for closed runs, fed-batch mode adds feed effects, and continuous mode uses steady flow balances. Enter all known values using consistent units.
For batch or fed-batch analysis, enter start and end times, initial and final volumes, product concentrations, and substrate concentrations. If you used a nutrient feed, enter feed volume and feed substrate concentration. Add average biomass concentration when you want specific product rate.
For continuous analysis, provide an observation interval, reactor volume, inlet flow, outlet flow, inlet product concentration, outlet product concentration, and substrate concentrations. The calculator then estimates net product generation, residence time, conversion, and productivity from steady state balance relationships.
After submission, the result block appears above the form. Review the output table, inspect the Plotly graph, then use the CSV or PDF buttons to save the results. Keep concentration, flow, biomass, and time units consistent for meaningful interpretation.
It measures how quickly a desired product is generated over time. Depending on your mode, it may be expressed as mass per hour, concentration increase per hour, or mass per volume per hour.
Use batch mode when material stays in the vessel without continuous inlet or outlet flow during the measured interval. It suits closed fermentation, synthesis, and reaction runs.
Fed-batch mode fits processes where additional feed enters during operation. The calculator includes feed substrate mass so the yield and conversion values better reflect the actual material balance.
Average biomass is only needed when you want a specific product rate. If you leave it blank, the calculator still returns total rate, productivity, yield, and conversion values.
N/A appears when a denominator is zero or missing. This prevents invalid divisions in yield, specific rate, residence time, or conversion calculations.
You should not mix units. Keep time, volume, concentration, flow, and biomass units internally consistent, or the reported rates and yields will not represent the real process.
Volumetric productivity shows how much product is generated per unit reactor volume per unit time. It is useful for comparing reactor efficiency across scales and operating conditions.
No. It is a planning and interpretation tool. Final conclusions should still be checked against measured balances, calibrated instruments, sampling quality, and process specific assumptions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.