Water wasted by leaks: the water and money you lose, and what a repair saves
A tap that has been dripping for weeks, a faint sound of water in the wall, or a pipe that seeped and was then repaired. The question is the same: how much is really being lost? And is it urgent? The amount of water wasted by leaks is measured in litres and in money, but the gap between a visible drip and a hidden hole under pressure can be several hundred times.
This guide covers three calculators on the Kashf site. The first is for a visible drip, the second for a hole in a pressurised pipe using a hydraulic formula, and the third works out what you have saved since you fixed the leak. You will see how each result is calculated, why the figures differ so much, and when putting off a repair becomes expensive.
What are the leak waste calculators and what do they give you?
Three estimating tools, each for a different kind of question:
- Drip Waste Calculator: counts the drops per minute from a tap or joint and gives you the litres wasted per month, plus their cost if you enter your usual consumption.
- Dynamic Hydraulic Leak Calculator: estimates the flow from a hole in a pressurised pipe from the hole diameter, network pressure and hours of leaking per day, then works out the extra on your bill.
- Water Savings Counter After Repair: takes the leak rate you measured before the repair and the repair date, and calculates what you have saved so far and what you will save each month and year.
The first two calculate the cost the same way: the difference between the bill for your usual consumption plus the waste and the bill for your usual consumption alone. By default they use Saudi NWC residential tiers in SAR with wastewater and VAT. On the English site you can set your own price per m³ and currency under “Tariff & currency”, so the cost fits your country. Volumes in litres never depend on the tariff.
Who are these tools for?
- Anyone who sees a drip and wonders whether it is worth calling a plumber now.
- Anyone who suspects a hidden leak and wants to understand the possible loss before booking.
- Anyone who has fixed a leak and wants a clear figure for what they saved, or to convince family or a landlord.
- Anyone interested in saving water at home or in a building.
When should you use them?
- When you notice a drip from a tap, mixer or water heater connection, before you get used to it and forget it.
- After a meter test that showed movement, to understand what the figure means in money.
- When deciding between fixing it now and fixing it “after the holidays”.
- Days or months after a repair, to calculate the accumulated savings.
Where do you use them?
All three calculators open in windows inside the tools hub on a phone or computer. Count the drops while you are at the tap itself, with your phone's clock. You can use the hydraulic calculator and the savings counter from anywhere, because they need figures, not observation.
What do you need before you start?
- Your usual monthly consumption in m³ from a bill before the leak appeared. It decides which tier the waste falls into.
- For the drip calculator: the number of drops in one minute. Count twice and take the average.
- For the hydraulic calculator: an estimate of the hole diameter in millimetres, and the network pressure if you know it (3 bar is a reasonable default for many homes).
- For the savings counter: the leak rate in litres per hour from a meter test before the repair, and the repair date.
Tools and how to use them, step by step
Drip Waste Calculator
A calculator for a visible drip. You move the “Approximate drips per minute” slider from 5 to 120 drops (default 30), and it calculates:
- Litres per day = drops per minute × 1,440 minutes × 0.25 ml (that is, × 0.36), assuming a drop of about 0.25 ml, the basis of the US Geological Survey (USGS) drip calculator. The tool states this assumption openly.
- Per month = daily × 30, with the equivalent in cubic metres.
If you enter a figure in the optional field “Your usual monthly consumption without the leak (m³)”, a line is added with the estimated monthly increase on your bill. The increase is the difference in the bill amount, using Saudi residential tiers with 50% wastewater and 15% VAT by default, or your own tariff from “Tariff & currency”.
Steps for correct use
- Count the drops for a full minute
Put a cup under the tap and count the drops for 60 seconds with your phone's clock, then count a second time. If the water runs as a thin continuous stream, this isn't a drip; use the hydraulic calculator or a meter test instead.
- Move the slider to your count
Drag “Approximate drips per minute” to the nearest value. The slider moves in steps of 5, and the result updates immediately with no button.
- Add your usual consumption to see the cost
Type a normal month's consumption from your bill in the optional field, for example 25. A line appears with the estimated increase on your bill per month.
- Repeat for each drip
The calculator handles one source. If more than one tap is dripping, calculate each one separately and add up the litres.
How to read the result
- Litres per month is the key figure. 30 drops per minute give about 11 litres a day and about 324 litres a month; 120 drops give about 43 litres a day and about 1,296 litres a month.
- Card colour and waste level: “Low waste” with no colour under 300 litres a month (up to 25 drops), “Medium waste” in orange from 300 to under 900 litres (30 to 80 drops), and “High waste” in red from 900 litres upwards (85 drops or more).
- The cost of a drip is usually small. 30 drops on top of 25 m³ of usual use add about SAR 0.6 a month under Saudi tiers, and more if your consumption is in a higher tier.
The honest conclusion: a visible drip wastes more water than money, and fixing it is usually simple, a new washer or cartridge. The big losses come from continuous leaks under pressure, which is what the next calculator covers.
Dynamic Hydraulic Leak Calculator
Estimates the water escaping from a hole in a pressurised pipe using the standard orifice flow equation: Q = Cd × A × √(2ΔP/ρ). The discharge coefficient Cd ≈ 0.6 for a sharp-edged orifice, A is the hole area, ΔP the network pressure and ρ the density of water. You set four inputs:
- Approximate hole diameter: 0.5 to 10 mm, default 2 mm.
- Water network pressure: 1 to 8 bar, default 3.
- Leak hours per day: 1 to 24, default 24.
- Your usual monthly consumption without the leak (m³): default 25.
The result: litres per day, cubic metres per month, and the estimated increase on the bill. The increase is the difference in the bill between (usual + waste) and usual, using Saudi tiers by default or your own tariff. The tool shows the full calculation method under the result, and warns that the real shape of the hole and your actual pressure are not precisely known.
Steps for correct use
- Estimate the hole diameter
Move “Approximate hole diameter”. A pinhole is about 0.5 mm, and a small crack in a joint is often equivalent to 1 to 2 mm. If you don't know, try 0.5, then 1, then 2 to see the range.
- Set the pressure and leak hours
Leave “Water network pressure” at 3 bar if you don't know yours. If the leak is after a pump that only runs part of the day, lower “Leak hours per day”.
- Enter your usual consumption
In “Your usual monthly consumption without the leak (m³)” type the figure from a bill before the problem started. It decides which tier the wasted cubic metres fall into.
- Read the result and the method
The result updates instantly with every change: litres per day, cubic metres per month and the cost increase. Read the methodology note underneath to see the assumptions.
How to read the result
- Card colour: orange if the increase exceeds 120 a month in your currency, red if it exceeds 400.
- Examples at 3 bar, 24 hours a day, on top of 25 m³ under Saudi tiers: a 0.5 mm hole gives about 250 litres a day and about SAR 21 a month. A 1 mm hole gives about 1,000 litres a day and about SAR 155. A 2 mm hole gives about 4,000 litres a day and more than SAR 1,000 a month.
- The result is an approximate ceiling for a clean hole. Cracks, loose joints and leaks into soil usually give less. Your real figure comes from a meter test.
If the result is orange or red and you have any sign of a leak, don't put off the inspection. The cost here adds up every day.
Water Savings Counter After Repair
A personal calculator for the water you have saved since you fixed a leak. It needs two figures:
- “Leak rate before repair (liters/hour)”: from a meter test, that is the reading difference in litres ÷ the test hours.
- “Leak repair date”; a future date is not accepted.
The calculation: savings so far = rate × 24 × whole days since the repair, shown as an animated counter in litres with the equivalent in m³. Then monthly savings = rate × 24 × 30, and annual = rate × 24 × 365. The tool states clearly that this is a personal estimate for your home, not a statistic about Kashf's customers.
Steps for correct use
- Get the leak rate from before the repair
Use the result of the meter test you ran before the repair. For example, 15 litres in 30 minutes equals 30 litres per hour. If you didn't measure it before the repair, don't guess a large figure.
- Enter the rate and the date
Type the figure in “Leak rate before repair (liters/hour)” (greater than zero), and choose the “Leak repair date” from the calendar.
- Tap “Calculate savings”
An animated counter shows the quantity you have saved, then a line with the days since the repair date in cubic metres, then “Ongoing savings at the same rate” per month and per year.
- Make sure the leak has really stopped
The tool assumes the leak stopped completely. Repeat the meter test after the repair; if it is green, the figure holds.
How to read the result
- The large animated figure: litres saved since the repair date. If you fixed it today, it is zero, because the calculation uses whole days.
- Monthly and annual savings: for example, a rate of 30 litres per hour means about 21,600 litres a month and about 262,800 litres a year, roughly 263 m³.
- To turn the savings into money, enter the monthly savings in m³ with your usual consumption into the Water Bill Waste Calculator. This tool doesn't calculate money.
If a meter test after the repair shows movement again, the leak hasn't stopped completely, or there is a second source.
Why does the waste vary so much?
A drip moves by gravity, so water escapes drop by drop. A hole in a pressurised pipe pushes water out with the full force of the pressure. Two rules in the orifice equation explain the difference:
- Flow is proportional to the hole area, and the area is proportional to the square of the diameter. A 2 mm hole lets out about 4 times as much as a 1 mm hole, not just twice as much.
- Flow is proportional to the square root of the pressure. Doubling the pressure from 2 to 4 bar raises the flow by only about 41%.
Then come the tariff tiers: the first cubic metres are cheap, and the extra ones fall into the most expensive tiers. That is why a medium leak quickly turns into tens or hundreds of riyals a month in Saudi Arabia, and the same pattern applies under any rising-block tariff.
The tiers used in the calculators are approximate and for comparison. The official reference is your bill and the National Water Company website.
Which calculator fits your case?
- You can see separate drops from a tap, mixer or visible joint: the Drip Waste Calculator.
- You suspect a hidden leak, or see seepage under pressure: the hydraulic calculator for the likely range, then a meter test for your real figure.
- You have fixed the leak and measured it beforehand: the Water Savings Counter.
- Your bill is high and you want to know why: that is the topic of the high water bill guide.
Why waste matters even more in Saudi Arabia
Much of the Kingdom's drinking water comes from desalinated seawater carried over long distances, a process that uses a lot of energy. Most homes have a tank and a booster pump, and a pump that runs more than it should to make up for a leak uses extra electricity and wears out faster.
In summer the soil and roofs get very hot, so plastic pipes and joints expand and consumption rises. A leak that was small in winter can grow. Water leaking under tiles or into foundations also costs more than the bill, because it causes damp and damage. See the damp stains and moisture damage guide.
Common mistakes that spoil the result
- Counting drops for 10 seconds and multiplying by 6: drips are irregular, so count a full minute, twice.
- Leaving usual consumption empty or at zero: the cost is then calculated in the cheap tiers and looks lower than it really is. Enter your bill figure.
- Choosing a large hole diameter “to be safe”: doubling the diameter quadruples the result. Try a range and don't base a decision on the worst figure.
- Entering a guessed rate in the savings counter: the tool is designed for a rate measured with a meter test.
- Forgetting that the waste counts water only: damage from damp and to finishes is not included in these figures.
The honest limits of the tools
- All results are estimates. Drop size isn't constant, and the 0.25 ml assumption (0.36 litres a day for each drop per minute, the basis of the USGS calculator) is approximate; reality can be higher or lower.
- The hydraulic equation assumes a clean, sharp-edged hole and constant pressure. Cracks, joints and the soil around the pipe change the result.
- Costs use approximate residential tiers with wastewater and VAT, or your own tariff. Commercial tariffs and other fees are not included.
- The savings counter assumes a steady leak all day that stopped completely after the repair.
- None of these tools detects a leak or finds where it is.
When do you need a leak detection technician?
- If the hydraulic calculator shows a large increase and you have a real sign: a moving meter, damp or the sound of water.
- If the drip is coming from inside a wall or ceiling, not from a visible tap.
- If you have fixed a leak and a new meter test shows movement again.
At Kashf, the technician locates the leak without demolition using acoustic sensors, thermal cameras, pressure testing and a safe tracer gas, so work happens only at the exact point. You receive a written inspection report with a verification code you can check on the verification page. Book through the order page or on WhatsApp 0544027180; on-site service is available in Saudi Arabia only. To see what sets the price, read the leak detection cost guide.
Frequently asked questions
How many litres a day does a dripping tap waste?
It depends on how fast it drips and the size of the drops. Our Drip Waste Calculator assumes a drop of about 0.25 ml, the basis of the USGS drip calculator, which is about 0.36 litres a day for each drop per minute. A tap dripping 30 times a minute wastes about 11 litres a day and 324 litres a month; one dripping 120 times wastes about 1,296 litres a month.
Does water wasted by leaks raise the bill much?
It depends on the type of leak. Water wasted by leaks from a dripping tap usually costs only a few riyals a month. A continuous leak under pressure can add hundreds, because the extra cubic metres are charged in the most expensive tiers. Under Saudi tiers, a 1 mm hole at 3 bar on top of 25 m³ of normal use can add an estimated SAR 155 a month.
How do I calculate the water lost from a hole in a pipe?
With the orifice flow equation used by the hydraulic calculator: flow equals the discharge coefficient times the hole area times the square root of twice the pressure divided by the density of water. You don't need to do it by hand: enter the diameter, the pressure and the leak hours, and the tool gives you litres, cubic metres and the cost.
Why does the result quadruple when the hole doubles in size?
Because the amount of water escaping is proportional to the area of the hole, and the area is proportional to the square of the diameter. So a 2 mm hole lets out about four times as much as a 1 mm hole at the same pressure. That is why a leak that grows over time becomes expensive so quickly.
What is the usual water pressure in a home?
It varies with the district, the distance from the network and whether there is a pump. The calculator starts at 3 bar as a reasonable estimate for many homes, and you can change it from 1 to 8 bar. If you want an exact figure, a technician measures it with a pressure gauge during the inspection. Note that pressure has less effect than the hole diameter.
How do I find my leak rate in litres per hour?
With a meter test: with every tap closed and the tank full, record two readings 30 minutes apart. The difference in litres divided by half an hour is the hourly rate. For example, 15 litres in 30 minutes equals 30 litres per hour. The Water Meter Test page calculates it for you automatically.
Does the savings counter show how much money I saved?
No. The Water Savings Counter only calculates litres and cubic metres: what you have saved since the repair, and what you will save per month and per year at the same rate. To see its value in money, enter the monthly savings in cubic metres with your usual consumption in the Water Bill Waste Calculator, which works out the difference using the tariff tiers.
Should I fix a dripping tap myself or call a technician?
A drip from a visible tap or mixer is usually fixed by replacing a washer or cartridge, and many people can do it themselves after closing the isolation valve. A drip from a ceiling or wall, or any leak whose source you can't see, needs an inspection with detection equipment to locate it before any demolition.
Are the calculators' figures accurate for my home?
They are estimates based on equations and general assumptions: an average drop size, a clean hole, steady pressure and residential tiers or your own tariff. They are useful for understanding the scale, comparing options and making a decision. The real figure for your home comes from a meter test, and the real amount from your official bill.
Related services
On-site inspections are available in Saudi Arabia; the tools and guides work anywhere.
This guide is educational. It explains estimation tools that help you understand a situation and decide what to do next; confirming a leak and pinpointing it always requires an on-site inspection with instruments. Structural questions are for a licensed engineer to decide.