About this site
This site is published by Miracle Ventures Ltd and sponsored by ADI Leak Detection, so treat this as a site with an interest in the answer rather than a neutral one. What does not change is the working: every figure carries the source it came from, every formula is written out, and every tool gives a complete answer without an email address, a sign up or a booking step.
Last reviewed 16 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.
It is a public utility rather than a lead capture form wearing a calculator costume. Every tool runs to a complete answer with no email gate, no interstitial, no modal and no booking step. A visitor who never contacts anyone still gets exactly what they came for.
Who publishes it and who funds it
This site is published by Miracle Ventures Ltd, a company that publishes informational sites. It is sponsored by ADI Leak Detection, which does leak tracing.
The sponsorship is stated at the top of every page rather than in the small print, because it is the thing a reader most needs in order to weigh everything else. An earlier version of this page called the site independent. It should not have, and the wording was corrected on 16 August 2026 rather than defended.
In practice the sponsor does not choose the constants, see a formula before it is published, review the wording, or ask for a result to be presented differently. That is true and it is worth saying, but notice what kind of claim it is: a description of how people behave, made by the people behaving. It is not a structural guarantee and this page will not dress it up as one. Weigh it accordingly, and weigh the sources page more.
The sponsorship appears in two places and nowhere else: the strip at the top of every page, and a bordered block below a calculator result. That block is the only element on the site with a border on all four sides, which is what makes it unmistakably not part of the calculation. Its content depends on the severity of your result, and below 0.5 litres per hour it offers no service at all, because the reading does not justify one.
The sponsor block is driven by a data file rather than built into the pages, so a second sponsor, or a different one, would be a data change rather than a rebuild. That is worth knowing about how the site is put together. It is not a claim about independence, and it used to be written as one.
How the site makes money
Three ways, in this order, and none of them depends on withholding a result.
- Sponsorship. ADI Leak Detection pays for the site to exist. That payment is not contingent on traffic, enquiries or outcomes.
- Referral traffic. Links to the sponsor are marked as sponsored links in the page markup, including logo and image links, so that they are machine-readable as advertising rather than as endorsement.
- Third-party sponsorship later, once the site has an audience. The sponsor block is already a slot rather than a hardcoded block, so that would change a data file rather than a component.
There is no per-click or per-enquiry payment, no affiliate arrangement, and no advertising network. Nothing on the site is paid placement dressed as a result.
Reporting an error in a calculation
If a number here is wrong, that is a defect and we want to know. A site whose entire proposition is that its numbers can be checked has to have a way of being told when one does not check out.
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 rather than measurements, 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
Naming a company is only part of what a company has to disclose on its own website. The registered number, the place of registration and the registered office address belong here too, and they have not been supplied yet. They have not been guessed at either, and the build refuses to publish while any of them is missing, which is the same rule applied to every other fact on this site that nobody has been able to source.
That gate is deliberately the same one that held this page back when the operator itself was unknown. Half a legal disclosure is not a step towards a complete one; it is a page that looks compliant and is not, and this site would rather show you the gap.
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 rather than on any particular figure, so the full list is shown rather than a filtered view that would look complete and would not be.
Common questions
- Who publishes this, and who pays for it?
- This site is published by Miracle Ventures Ltd, which publishes informational sites. It is sponsored by ADI Leak Detection, which does leak tracing. The sponsorship is stated at the top of every page and on every link to them, so you can see it wherever you land rather than having to come here for it.
- So is this independent?
- Treat it as sponsored, because it is. ADI Leak Detection funds this site, and that is stated at the top of every page. Do not take independence on trust here. Take the working instead. Every figure these calculators use is listed on the sources page with its provenance and a grade, ordered worst first. Every formula is written out. Where a number is our assumption rather than a published figure, the page that uses it says so and shows how far the answer moves if the assumption is wrong. That is checkable whoever owns what, and it is the only assurance worth giving.
- How would I know if the figures were being leaned on?
- The sources page grades every figure on the site by the strength of its evidence and orders it worst first, so the first thing a reader meets there is our own weakest evidence, graded at the bottom of our own scale. Below half a litre an hour the site offers no service at all and says the reading does not justify one, which is the opposite of what a lead funnel does with a visitor who has bothered to measure. Neither is proof of anything. Both are behaviour you can check, which beats a promise you cannot.
- Do you make money if I contact the sponsor?
- The site is funded whether you do or not. There is no per-click or per-enquiry payment, and no calculator changes its answer based on whether a service is being offered underneath it. The lowest severity band offers no service at all, deliberately, 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 rather than 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.