Pipe Volume Calculator
This pipe volume calculator takes the outer or inner diameter, wall thickness and length and gives the water content of the pipe in litres, per metre of pipe, and the time to flush it.
Example: Diameter given as: Outer diameter (with wall thickness) · Diameter 22 mm · Wall thickness 1 mm · Pipe length 10 m · Flow at the tap (optional) 6 l/min → Content: 3.14 litres of water. Source: Wikipedia – Zylinder (Geometrie): Volumen V = π · r² · h. Updated: .
How it is calculated
A 22 × 1 mm copper tube holds just over 3 litres of water per 10 metres. Pipe volume is the volume of the hollow inside the pipe, a cylinder with the inner diameter.
How it is calculated
The inner diameter gives the cross-section π/4 · d². Multiplied by the length this is the volume. If you enter the outer diameter, the calculator subtracts the wall thickness twice. Because 1 litre equals one cubic decimetre, the content can be given directly in litres; the water weighs about one kilogram per litre. With the flow at the tap you also get the time until the water in the pipe has been replaced once.
What the figure is used for
- Filling and bleeding heating and water pipes, sizing expansion vessels.
- Estimating how long hot water takes to arrive and how much water runs off unused.
- Preparing flushing, pressure tests and disinfection.
Frequently asked questions
How do you calculate pipe volume?
V = π/4 · inner diameter² · length. With d and length in decimetres you get litres directly; the calculator handles the conversion.
What is the inner diameter if I know the outer diameter?
Inner diameter = outer diameter − 2 · wall thickness. For copper 22 × 1 mm this is 20 mm.
How much water fits in a metre of pipe?
About 0.31 litres at 20 mm inner diameter and about 0.20 litres at 16 mm. The calculator shows litres per metre for your pipe.
How many gallons is that?
Divide litres by 3.785 for US gallons or by 4.546 for imperial gallons.
Sources and legal basis
- Wikipedia – Zylinder (Geometrie): Volumen V = π · r² · h
- Wikipedia – Cylinder: Volume of a cylinder
- Wikipedia – Properties of water (Dichte etwa 1 kg/l)
As of: · Editorial policy
Related tools
- Leaky faucet calculatorLeaky faucet calculator: count the drips per minute and see how many gallons a dripping faucet wastes per day, month and year – and what it costs.
- Volume CalculatorVolume calculator for 12 shapes: cylinder, box, sphere, cone, prism, horizontal tank … Mix cm, m, inches and feet – with litres, gallons, formula and sketch.
- Cylinder CalculatorCylinder calculator from any two values: radius, diameter, circumference, height, volume, lateral or surface area – with formulas, litres and working.
- Liters to gallons converterConvert liters to gallons and back: 1 liter = 0.2642 US gallons. Also UK gallons, pints, cups, cubic meters and barrels – with the working and a table.
- Pool Volume Calculator – How Many Gallons Is My Pool?Pool volume calculator for rectangular, round, oval and kidney pools: enter size and depth, see gallons and liters – plus fill time and pump turnover time.
- Daily water intake calculatorHow much water should you drink a day? Daily fluid and total water intake by age, sex, pregnancy and breastfeeding, based on EFSA and German DGE values.
- kg to lbs converterConvert kg to lbs and back: 1 kg = 2.2046 lb. Shows pounds and ounces, stone and pounds, grams, tons and a kg to lbs chart – exact to the legal definition.
- UTC to EST time converterUTC to EST: subtract 5 hours in winter (EST) and 4 hours in summer (EDT). Enter a UTC time and date for New York time, with live clocks and a full-day table.
- Acres to square feet converterAcres to square feet: 1 acre = 43,560 sq ft. Enter acres to get square feet at once, or go back from sq ft to acres – with m², hectares and lot-size examples.