# How to calculate leakage through a hole in a pipe
**URL:** https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106
**Category:** Factual Questions
**Created:** [January 20, 2012, 4:55am UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106 "2012-01-20T04:55:42Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Oly](https://boards.straightdope.com/u/Oly)
#### Post date: [January 20, 2012, 4:55am UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/1 "2012-01-20T04:55:42Z")
Say, there is a small hole in a pipe, through which water flows at a constant rate. Using the size of the hole (known), how do I calculate the rate of leakage? Thanks.
---
### Author:  [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)
#### Post date: [January 20, 2012, 4:59am UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/2 "2012-01-20T04:59:41Z")
Any reason you can’t measure it?
---
### Author:  [@Oly](https://boards.straightdope.com/u/Oly)
#### Post date: [January 20, 2012, 5:08am UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/3 "2012-01-20T05:08:53Z")
> [@Snarky\_Kong](#):
>
> Any reason you can’t measure it?
Actually, I do know the volume of the leaked amount. What I am really interested in is how much time it took from when the leak started to accumulate that volume, or how long the leak had been there.
---
### Author:  [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)
#### Post date: [January 20, 2012, 6:18am UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/4 "2012-01-20T06:18:48Z")
How to Calculate the Fluid Flow Through a Hole in a Pipe:
> **[How to Calculate the Fluid Flow Through a Hole in a Pipe](https://sciencing.com/calculate-flow-through-hole-pipe-5885513.html)**
>
> Calculate the volume of fluid flowing through an opening in a hole in the side of a pipe given the diameter of the pipe and the position of the hole.
---
### Author:  [@Oly](https://boards.straightdope.com/u/Oly)
#### Post date: [January 20, 2012, 1:56pm UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/5 "2012-01-20T13:56:38Z")
> [@engineer\_comp\_geek](#):
>
> How to Calculate the Fluid Flow Through a Hole in a Pipe:
> [How To Calculate The Fluid Flow Through A Hole In A Pipe](http://www.ehow.com/how_5885513_calculate-flow-through-hole-pipe.html)
Yes I saw this. My misgivings about it are the calculations for the fluid velocity in step 3. Given that they are using height of the surface of the water above the hole and the acceleration of gravity, I assume the situation they are modeling is something like water falling down a gutter pipe (if I’m wrong, please correct me, I’m flying blind here). In that system, the water pressure is determined only by those factors.
What I have is a closed system where the pressure is generated by a pump. (To be more specific, I am trying to figure out how long it would take to bleed a known volume of blood given a hole of known size in a major artery. Just idle curiosity.)
---
### Author:  [@zut](https://boards.straightdope.com/u/zut)
#### Post date: [January 20, 2012, 3:07pm UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/6 "2012-01-20T15:07:00Z")
Hydraulic engineers will often talk about “feet of head,” where the pressure at a point in the system is represented by the number of feet of fluid required to produce that pressure hydrostatically. Try [this calculator](http://www.pumpcalcs.com/calculators/view/103/) as an example; it will give the step-by-step equations, including turning psi into feet of head. (The specific gravity of water is 1, and I’d use an orifice constant of 0.62).
It’s not that you have to switch to “feet of head,” though; that’s just the standard terminology that some people use. It’s simpler, I think, to use the standard orifice equation, described [on this Wikipedia page](http://en.wikipedia.org/wiki/Orifice_plate). That is:
Q = C[sub]d[/sub]A\*sqrt(2[symbol]D[/symbol]P/[symbol]r[/symbol])
where C[sub]d[/sub] is the orifice coefficient (0.62 is a good guess) A is the area, [symbol]D[/symbol]P is the pressure difference across the hole, and [symbol]r[/symbol] is the fluid density. This equation in turn comes from Bernoulli’s equation and continuity, as described on the Wikipedia page.
---
### Author:  [@nabila](https://boards.straightdope.com/u/nabila)
#### Post date: [October 17, 2016, 12:45pm UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/7 "2016-10-17T12:45:27Z")
Hello and hi, i have the quite same question maybe, but not exactly same. Then i need to calculate the volume leakage of underground pipeline.
The information i got are:
Duration for leakage=10min
Diameter of leakage=3’’
Flowrate inlet throughout the pipeline=987m3/hr
Length of pipeline=500m
Pressure at 10 bar
So can you guys give some guide or step for me to follow to get the correct or estimation value for leakage volume?
---
### Author:  [@nabila](https://boards.straightdope.com/u/nabila)
#### Post date: [October 17, 2016, 11:22pm UTC](https://boards.straightdope.com/t/how-to-calculate-leakage-through-a-hole-in-a-pipe/610106/8 "2016-10-17T23:22:36Z")
Hello and hi, i have the quite same question maybe, but not exactly same. Then i need to calculate the volume leakage of underground pipeline.
The information i got are:
Duration for leakage=10min
Diameter of leakage=3’’
Flowrate inlet throughout the pipeline=987m3/hr
Length of pipeline=500m
Pressure at 10 bar
So can you guys give some guide or step for me to follow to get the correct or estimation value for leakage volume?