About this site
This site belongs to ADI Leak Detection, who find and repair leaks, and Miracle Ventures Ltd publishes it. We have an interest in the answer and we are not going to pretend otherwise. What you can check is the working. Every figure says where it came from, the formulas are written out on the page, and you get the full answer without handing over an email address or booking anything.
Last reviewed 27 August 2026
What this site is
Tools that quantify water loss in UK properties and convert it into litres, cubic metres, and cost.
That sentence is the test every page here has to pass. If a page cannot be derived from it, the page does not belong on the site, and several proposed pages have been deleted on exactly that basis.
Every tool runs through to a complete answer. There is no email gate, no pop-up and no booking step anywhere in it. If you use the site and never speak to anybody, you still get what you came for.
Whose site this is
This site belongs to ADI Leak Detection, who trace and repair leaks. It is published by Miracle Ventures Ltd, whose registered details are further down this page.
An earlier version of this page called the site independent. It should not have, and we corrected the wording on 16 August 2026 instead of arguing about it. After that the page described a sponsorship, which stopped being accurate once the site was branded as ADI’s, and that was corrected on 27 August 2026.
In practice ADI do not pick the constants, see a formula before it goes up, check the wording, or ask for a result to be shown differently. That is true. It is also us describing our own behaviour on a site we own, so there is nothing stopping us from changing our minds about it tomorrow, and you have only our word that it has been true so far. Put much more weight on the sources page.
Where ADI Leak Detection appears here
In four places. They are listed here so you can tell an advertisement from a result at a glance.
- The masthead of every page, as their mark beside the site name.
- The foot of every page, as their mark, telephone number and web address.
- A band at the bottom of the home page, describing what they do.
- A bordered block below a calculator result, which names them in its own heading.
Only the last of those sits anywhere near a figure. It is the one thing on the whole site with a border all the way round it, so it should be hard to mistake for part of your result. What it says depends on how bad your reading is, and below 0.5 litres per hour it offers you nothing, because a reading that small does not justify calling anyone out.
Every link to them anywhere on the site, including the logo links, is marked as a sponsored link in the page markup, so a machine reads it as advertising and not as a recommendation.
That block is driven by a data file instead of being built into the pages, so putting a different advertiser there, or several, would mean editing one file. Worth knowing about how the site is put together. It says nothing about independence, though an earlier version of this page tried to use it that way.
How this site is paid for
ADI Leak Detection pay for it to exist. That payment is not contingent on traffic, enquiries or outcomes, and nothing on the site depends on withholding a result.
There is no per-click or per-enquiry payment, no affiliate arrangement, and no advertising network. Nothing here is paid placement dressed as a result, and no third party has bought space on any page.
Reporting an error in a calculation
If a number here is wrong, we want to know. The whole point of publishing the sources is that you can check them, so there has to be somewhere to report it when one of them does not hold up.
Corrections: [email protected]
The most useful report names the page, the figure and what you believe it should be, with the source you are using. A figure that disagrees with its own cited source is the highest priority correction there is, because it means the site is misrepresenting somebody else’s work.
Before reporting, it may be worth checking every citation on this site, graded and ordered worst first, which states the strength of the evidence behind each figure. Some numbers here are labelled assumptions, and those are meant to be disagreed with rather than corrected.
Who operates it
This site is operated by Miracle Ventures Ltd.
Registered name: Miracle Ventures Ltd
Company number: 09819220
Registered in: England and Wales
Registered office: C/O Carroll Accountants Unit L, Bpi House, Cores End Road, Bourne End, Bucks, England, SL8 5AS
A company has to give more than its name on its own website. The registered name, the number, where it is registered and the registered office all belong here too, and all four are above. For two days in August 2026 only one of them was known, and the build refused to publish the page at all until the rest turned up. A page showing half a legal disclosure looks compliant without being it, which seemed worse than showing the gap.
That check is still in place. If any of the four goes missing, or gets recorded on anything weaker than a reading of the register itself, the build stops.
Assumptions and sources
Drip Calculator: how much water does a leaking faucet waste?
United States Geological Survey, Water Science School · primary source
- Faucet drip volume, adopted: 0.25 ml
- Faucet drip volume, measured range: 0.2 to 0.33 ml
- Bath tap drip volume: 0.5 ml
- Drips per US gallon: 15140 drips
- Drips per litre: 4000 drips
The pharmacopoeial metric drop, 20 drops to 1 millilitre
United States Pharmacopeia, British Pharmacopoeia and European Pharmacopoeia convention · primary-standard source
- Standard drop volume: 0.05 ml
Tate's law: the weight of a falling drop
Thomas Tate, Philosophical Magazine, 1864, with the later drop-weight literature · primary source
- Drop weight: W = 2 * pi * r * gamma equation
Plumbers shine the spotlight on dripping taps during Water Saving Week
WaterSafe, with Waterwise · untraceable source
- Claimed annual waste from a dripping tap: 5500 litres per year
International Organization of Legal Metrology · primary-standard source
- MPE, accuracy class 2, lower zone Q1 to Q2: 5 %
- MPE, accuracy class 2, upper zone Q2 to Q4: 2 %
- MPE, accuracy class 1, lower zone: 3 %
- MPE, accuracy class 1, upper zone: 1 %
- In-service MPE multiplier: 2 ratio
- Q2 / Q1: 1.6 ratio
- Q4 / Q3: 1.25 ratio
Aquadis+ DN15 and DN20 specification sheet
Itron · manufacturer source
- Q1 minimum flow rate, DN15, Q3 2.5, R160: 15.6 l/h
- Q2 transitional flow rate, DN15, Q3 2.5, R160: 25 l/h
- Q3 permanent flow rate, DN15: 2500 l/h
- Typical starting flow rate, DN15: 0.4 l/h
- Typical starting flow rate, DN20: 2 l/h
- Q1 minimum flow rate, DN20, Q3 4.0, R160: 25 l/h
- Flow rate at which accuracy is within +/- 5%, DN15: 3 l/h
- Flow rate at which accuracy is within +/- 2%, DN15: 5 l/h
- Minimum scale interval, DN15 and DN20: 0.02 l
Water resources 2024 to 2025: analysis of the water industry's annual water resources performance
Environment Agency · primary source
- Household per capita consumption: 136.5 l/person/day
- Household per capita consumption, prior year: 137 l/person/day
- Household per capita consumption, dry-year adjusted: 140.3 l/person/day
- National leakage: 2617 Ml/day
- National leakage as share of water put into supply: 19 %
PR24 common performance commitments: per capita consumption (PCC), version 2.1
Ofwat · primary-standard source
- PCC formula: (measured household consumption + unmeasured household consumption) / total household population l/person/day
Leaky loos, why it's not as simple as faulty flush valves
ech2o, reporting research attributed to Thames Water · secondary source
- Toilets inspected: 58551 toilets
- Toilets found leaking: 4854 toilets
- Prevalence: 8.3 %
- Average residential leak rate: 400 l/day
- Average commercial leak rate: 2100 l/day
- UK-wide average across all WCs, leaking and sound: 20 l/day
- Share of leaking toilets with flush valves rather than siphons: 81 %
Waterwise · untraceable source
- Single leaking toilet: 215 to 400 l/day
- Share of toilets leaking: 5 to 8 %
- UK total from leaking toilets: 400000000 l/day
Methods for Calculation of Evaporation from Swimming Pools and Other Water Surfaces
M. M. Shah, ASHRAE Transactions SE-14-001 · primary source
- Outdoor unoccupied pool evaporation: E0 = (C1 + C2 * u) * (pw - pa) / ifg kg/(m2*h)
- C1, SI: 235 constant
- C2, SI: 206 constant
Location-specific long-term averages, Wisley, Surrey
Met Office · primary source
- Annual mean daily maximum temperature: 15.41 degrees C
- Annual mean daily minimum temperature: 6.66 degrees C
- Annual rainfall: 667.92 mm
- Annual mean wind speed at 10 m: 5.06 knots
Discover Water, the water industry transparency site run with Water UK, Ofwat, CCW, the Drinking Water Inspectorate and Defra · primary source
- Average annual household bill, combined water and sewerage: 639 GBP
- Average annual household bill, water only: 309 GBP
- Average annual household bill, sewerage only: 330 GBP
SI Brochure: The International System of Units (SI), 9th edition (2019), version 4.01, June 2026
Bureau International des Poids et Mesures · primary-standard source
- cubic metre: coherent derived unit of the SI, Table 5 m3
- litre: non-SI unit, Table 8. 1 l = 1 L = 1 dm3 = 10^-3 m3 l or L
- bar: non-SI unit, Table 8. 1 bar = 0.1 MPa = 10^5 Pa bar
Authority URLs for the named entities in content/entities.ts
Various, see per-entity notes · primary source
WC flush volume: three UK instruments, not one
UK Statutory Instruments, Northern Ireland Statutory Rules, and Scottish Water · primary-standard source
- Maximum single flush, all three jurisdictions: 6 litres
- Dual flush, lesser flush maximum: two-thirds of the largest flush volume ratio
- England and Wales transitional maximum, 1 Jul 1999 to 1 Jan 2001: 7.5 litres
Per-event central heating top-up volume, derived
Derived by Q3 from Boyle's law and typical UK domestic expansion vessel specifications · derived source
- Water held in an expansion vessel: V_water = V * (1 - P0 / P), pressures absolute equation
- Typical top-up, 8 l vessel at 1.0 bar pre-charge, 0.5 to 1.5 bar: 1.6 litres
- Typical top-up, 8 l vessel at 0.75 bar pre-charge, 0.5 to 1.5 bar: 2.4 litres
- Typical top-up, 12 l vessel at 1.0 bar pre-charge, 0.8 to 1.5 bar: 2.4 litres
- Typical top-up, 8 l vessel at 1.0 bar pre-charge, 1.2 to 1.5 bar: 0.9 litres
- Realistic range: 0.9 to 2.5 litres
Monodispersed Bubble Generation Using Hydrophobic Orifices: The Extended Tate’s Law
Bo Liu, Hao Zhang and co-authors, ACS Omega 2024, 9(17), 18854 to 18861 · primary source
Every constant this site uses is listed above with its value, its unit and where it came from. This page rests on the whole of that, so the full list is shown and not a filtered view that would look complete and would not be.
Common questions
- Whose site is this?
- It belongs to ADI Leak Detection, who do leak tracing and repair. It is published by Miracle Ventures Ltd, whose registered details are set out further down this page. Their mark is in the masthead and the footer of every page here, so whose site this is should not be something you have to go looking for.
- So is this independent?
- No. The site belongs to a company that sells leak detection, so treating it as impartial would mean believing the one claim on here nobody can verify. Look at the working instead. Every figure these calculators use is listed on the sources page with a grade for how good the evidence behind it is, and the weakest ones come first. The formulas are written out. Where a number is our assumption and not a published figure, the page says so and shows you how much the answer moves if we have it wrong. You can check all of that yourself whoever happens to own the site.
- How would I know if the figures were being leaned on?
- Two things you can look at. The sources page grades every figure by how good the evidence behind it is, worst first, so the first thing you meet there is the weakest number on the site marked down by us. And below half a litre an hour we offer you nothing and tell you the reading does not justify calling anyone, which is the opposite of what a site chasing enquiries would do with someone who has just taken a measurement. Neither proves anything on its own. They are both things you can go and look at, which is more than a promise gives you.
- Do you make money if I get in touch with ADI?
- ADI Leak Detection is a business and this site is theirs, so yes: if you become a customer, they earn. Nothing is hidden in that. What does not happen is that no calculator changes its answer according to whether a service is offered underneath it, there is no per-click or per-enquiry payment to anybody, and the lowest severity band offers no service at all because the reading does not justify one.
- Do you use cookies or track me?
- There is no cookie banner because there is nothing to consent to. No third-party analytics, no advertising pixels, no tag manager, and no third-party network request at all while you use the site.
- Can I quote a figure from this site?
- Yes, and it is what the site is built for. Quote the figure with its own source and not with this site, because every number here carries the publisher it came from. If our source and our number disagree, the source is right and we want to know.