Calculate hydraulic retention time from tank volume and volumetric flow.
| Detention time | – |
Use this calculator for wastewater or reactor sizing when you know basin volume and the flow through it and want contact time.
HRT = V / Q. Keep volume and flow in matching units so time comes out in hours or minutes as you intend, for example m³ and m³/h → hours, or litres and L/min → minutes. There is no automatic unit conversion here because the time unit is whatever Q’s time base is.
Volume V: Tank or basin volume, for example cubic metres.
Flow Q: Volumetric flow in the matching unit per time, m³/h if volume is m³ and you want hours. Must be greater than zero.
Detention time: V / Q in the time unit implied by the flow.
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