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Tank Drain Time Calculator

Calculate how long it takes to drain a tank from one liquid level to another through a bottom orifice. Ideal for sizing drain valves, planning tank cleanouts, or verifying emergency drainage rates.

Initial Liquid Height (m)

Final Liquid Height (m)

Tank Cross-Section Area (m²)

Drain Orifice Area (m²)

Discharge Coefficient

Fill in the required fields to see your result.

Fluid Mechanics

Reynolds Number Calculator

Compute the Reynolds number to determine whether pipe or channel flow is laminar, transitional, or turbulent. Useful for selecting friction-factor correlations, sizing pipes, and predicting heat-transfer or mixing behavior.

Flow Velocity (m/s)

Pipe Diameter (m)

Kinematic Viscosity (m²/s)

Fill in the required fields to see your result.

Key differences

	Tank Drain Time Calculator	Reynolds Number Calculator
Category	Fluid Mechanics	Fluid Mechanics
Inputs required	5	3
Result	Drain Time (seconds)	Reynolds Number
What it does	Calculate how long it takes to drain a tank from one liquid level to another through a bottom orifice. Ideal for sizing drain valves, planning tank cleanouts, or verifying emergency drainage rates.	Compute the Reynolds number to determine whether pipe or channel flow is laminar, transitional, or turbulent. Useful for selecting friction-factor correlations, sizing pipes, and predicting heat-transfer or mixing behavior.