About Nest Quantum

Who runs this

Nest Quantum is built and maintained by one developer. That is the whole of it, and it is worth saying plainly, because sites like this one usually imply something larger and a claim you cannot check is worth nothing.

What you can check is the method. Every calculator on this site publishes the constants it uses, what each one is, where it came from, and when that source was last read. Where a figure has no published source, it says so and shows the arithmetic that produced it instead of citing something that does not contain it. That is unusual, it is the whole point, and it takes about thirty seconds to verify on any calculator here.

How a calculator gets built, and what stops it shipping wrong

A calculator is a formula, a set of constants, and a page. The formula is written once and tested against worked examples. The constants are recorded separately with their sources, and the page reads both, so what you see is what runs.

Nothing ships unless all of this passes:

• Every constant that carries a figure has a provenance record naming its source or showing its derivation. There are 181 of them across 60 calculators, citing 11 documents from 6 publishers.
• Every equation written into the prose is parsed and evaluated. If a worked example says 302 sq ft × 2 coats × 1.10 waste ÷ 350 = 1.90 gallons, a script checks that it does. It caught the first version of this very sentence, which had dropped the waste factor and did not add up.
• No formula may return an impossible answer. A division that could produce infinity is caught, and a payback period that never arrives is reported as never rather than as zero.
• Every page is measured for contrast, for keyboard access, and at eleven screen widths from 320 pixels up, in both light and dark themes.
• Every figure the results panel shows is compared against a stored baseline, so a change to a formula cannot silently change an answer.

These are gates, not intentions: they run on every change and they fail the build. The full method is set out in the methodology.

Why this exists

Most calculators on the internet will give you a number and no way to tell whether it is right. They do not say what coverage rate they assumed, what waste factor is baked into the total, or where the price came from. When the number is the basis for a purchase, that is not good enough: buying 15 per cent too much concrete means paying for bags you will never open, and buying 10 per cent too little paint means stopping mid-wall.

So every number here is traceable. If the answer is wrong for your job, you can find out which assumption made it wrong and change it, rather than guessing whether to trust the tool.

How this is paid for

Advertising. Nest Quantum carries Google AdSense and nothing else: no affiliate links, no sponsored calculators, no paid placements, and no arrangement with any manufacturer or supplier. Nothing on this site is here because someone paid for it to be.

That matters for a site that produces cost figures. No supplier, manufacturer or contractor has any influence on what a calculator says, because none of them is paying for anything. Where a comparison comes out unfavourable, the calculator says so: a payback period that never arrives is reported as never, and a saving smaller than its cost is shown as a loss.

The calculators are free, there are no accounts, and nothing you enter is sent anywhere. What that means in detail is in the privacy policy.

What this is not

These are planning estimates. They are good for deciding what to buy and roughly what it will cost, and they are not a quote, a measurement or a professional opinion. They do not know your local prices, your surfaces or your building, and structural, electrical, plumbing and permit-required work is governed by local code and an inspector rather than by a calculator.

A contractor's written number is binding. Ours is not, and no page here pretends otherwise.

If a number here is wrong

It might be. 181 constants across 60 calculators is a lot of figures, sources move, and prices change. Every published working ends with a link to report one, and the fastest way to find a mistake is for somebody to check it against the thing in front of them.

Send what you found and what you expected to [email protected], or use the contact page. Replies come within two working days. Where a correction changes an answer it is made in the code, the constant's record is updated, and the change is logged on the corrections page with what the site said before, rather than quietly deployed.