Plumbing & Pipe Flow Calc – Tank Fill/Drain Time

Use this endpoint when you need a quick, paid-per-call calculation of tank fill or drain time from flow rate and volume without setting up your own fluid-dynamics formula. It is especially useful when the tank is cylindrical and you only know diameter and depth rather than pre-computed volume, or when you need to account for simultaneous outflow reducing the net fill rate. Prefer it over general math APIs because it handles unit conversion between gallons and litres natively and returns a structured, human-readable summary.

• Missing required inflowGpm parameter returns an error
• Outflow equals or exceeds inflow returns an indeterminate or infinite fill time
• Providing neither volumeGallons, volumeLiters, nor both tankDiameterInches and waterDepthInches returns an error
• Negative flow values may produce unexpected results
• Non-numeric query parameter values will cause a parse error