The General Pluming Calculator formulas include the following: Rolling Offset Lengths Pipe Grading

• Rolling Offsets (Run and Travel)  – The Rolling Offset (Run) function computes the run and travel length a rolling offset based on the offsets and fittings. (see diagram).
• Pipe Grading - Compute the drop needed over a run for a grade (e.g. 1/8" over 12").
• Pipe Volume - Computes the volume in a pipe
• Pipe Contents Weight - Computes the weight of liquid in a pipe.
• Diagonal of a Box - The distance between to opposing corners of a box shaped structure (room, closet)
• Pipe Surface Area - This computes the inner or outer surface area of a length of pipe.
• Diagonal of a Box - This computes the length of the diagonal of a box (T) based on sides of length R, S and U.
• Flow Rate - This computes flow rate based on the total volume and the time it took to accumulate.
• Pipe Flow Volume  - This computes the total volume from a pipe based on the flow rated and the duration of flow.
• Weight of Water in a Tank - Computes the weight of water in a cylinder based on the radius and height (or length).
• Weight of sea water in pipe Inside of cylindrical water tank (e.g. hot water tank) 
• Pressure Head - The Potential Gravity-Fed Water Pressure from a Tank (a.k.a. Pressure Head) equation calculates the water pressure that can be realized below a tank based on the height of storage.

Other Plumbing Calculators

• Weight of Pipe Contents: Default is water.  Also see 
• Volume of a Cylindrical Container (e.g. hot water tanks),
• Weight of Water in a Cylindrical Tank (e.g. hot water tanks),
• Volume of a Spherical Container,
• Weight of Water in a Spherical Container
• Volume of a Rectangular container
• Weight of Water in a Rectangular Container, and a 
• mean density lookup function that provides the mean density of hundreds of substances. 
• Capillary Rise - The height of water in a small tube due to capillary force.
• Snow Water Equivalence - The volume of water created by an area and depth of snow.
• Pore Water Pressure - Pressure of uplift from the water table.

The mean density (mD) can help the user calculate the content weight of containers (pipes and tanks) that hold substances other than water (e.g. diesel fuel or sludge).  The calculations require the user to enter the dimensions of the object (e.g. pipe, tank) to compute the volume.  For the weight equations, use the dimensions and the mean density of the substance in the object.  Note: The mean density of water is 1,000 kg / m³. Use this in the mass/weight equations to approximate the weight of water in the tank or pipe.

See Also

• Common Mean Densities - This equation returns the mean density of hundreds of substances.  If something beside water (~1,000 kg/m²⁾ is in the pipes or tanks, the mean density for that substance may be in this list. 
• House Builder - This is a foundation, framing and roofing calculator.