Short terms, because
the arrangement is small.

A terms document on a commercial service is a contract: it governs an account, a subscription, stored data and money changing hands. None of those is present. Rate & Sum is a set of public pages that compute in your browser, and using one is closer to reading a reference book than to signing up for something. So this page is deliberately short, and where a clause would be ceremony it has been left out and said to be left out.

It is also written in plain English by the person who maintains the calculations, and no lawyer has read it. That is stated rather than implied because the alternative — the register of a document that has had legal review, on a page that has not — would be the same kind of borrowed authority as a tax figure nobody checked. If a sentence here is legally imprecise, it is imprecise in plain view.

Three other pages carry rules that are theirs rather than restated here, and each is more specific than this page could be:

• What the numbers are and are not. The disclaimer lists what every individual calculator leaves out, tool by tool, which is the part that matters when a figure does not match your lender's.
• What happens to what you type. The privacy policy covers that, including the one case where figures do travel: a link that already carries them in its query string.
• Cookies and stored data. The cookie policy lists each one individually, with what it is for and how long it lasts.

Nothing on this page asks you to agree to anything by continuing to read. There is no acceptance step because there is nothing to accept — no account, no payment and no data of yours held here. The statements below describe how the site works and what it does not claim, which is true whether or not anyone reads them.

Using a calculator here does not make you a client, a customer or an applicant, and it does not make anyone here your adviser, broker, agent, accountant or representative. There is no engagement, no retainer and no professional duty running in either direction, because nobody here is licensed or regulated to owe one. A result on the screen is arithmetic you asked for, not a recommendation somebody made to you.

That matters most in the direction people do not expect. A figure produced here carries no authority with anyone: a lender is not bound by an affordability number this site printed, a servicer will not honour a payoff date it computed, and a tax authority has no interest in what a page of ours estimated. Those institutions have the contract and the actual figures. This site has a formula.

Nor is there any arrangement with the organisations whose material is cited. The site links out to 16 outside domains — regulators, federal agencies and, where a published example is the clearest illustration of a convention, a commercial lender's own explainer. None of them has reviewed anything here, none has authorised anything here, and no money moves between them and this site in either direction.

Nothing here is an offer, a solicitation or a quote for any loan, card, account, policy or investment, and no page on this site can be accepted as one. If you need a number you can rely on, the institution that would actually be lending or paying is the only place it can come from. The same rule applied to writing rather than arithmetic is on the editorial policy page.

This is the section the site was missing, and it is worth separating three things that a single copyright line would lump together — because the answer is different for each, and only one of them is restricted at all.

Your results

Yours, with no conditions. A payment figure, an amortisation schedule, a payoff date or a chart you produced by typing your own numbers is your output, and you may print it, save it, paste it into a spreadsheet, send it to your lender or publish it. Nothing needs asking for and nothing needs crediting. It would be absurd for a page that never sees your figures to claim rights over what they produced.

The formulas

Not ours to license. A method of computing a loan payment is a procedure, and United States copyright law puts a procedure, process, system or method of operation outside copyright protection regardless of how it is described or explained — 17 U.S.C. 102(b). So the arithmetic printed beside each result can be implemented, taught or checked by anyone, and the reason each page prints its formula in full is that this is the only way a reader can verify the answer.

The writing and the code

The prose, the page design and the source of this site are ours, and this is the one place a limit applies: please do not republish the explanatory writing wholesale as though it were yours. Quoting a passage with a link back is welcome and needs no permission. What is not welcome is the practice this site was built against — copying the explanations into a near-identical page so that two URLs answer one question, which is a worse result for everybody who searches for it.

Reading the site with automated tools is fine within reason, and "within reason" has a definition rather than being a threat: at a rate a person could plausibly browse at, and without making the site slower for anyone else. Every page here is static, so a considerate crawler costs nothing. If what you want is the method rather than the markup, the methodology page states each formula and the conventions it follows, which is more useful than scraping the rendered output.

One thing is explicitly not permitted: republishing our figures with the assumptions stripped off. Every number here is only meaningful alongside the compounding convention, rounding rule and exclusions printed beside it. Lifting the result and dropping the conditions produces a confident figure nobody can check, and that is the failure mode this entire site exists to avoid.

Most acceptable-use lists are long because the service has accounts, uploads, messages and other users to protect. This one has none of those, so the list is confined to things that could actually happen. Please do not:

• Attempt to interfere with the site's availability for other readers, or probe it in a way designed to break it rather than to understand it.
• Present the site, or a copy of it, as being operated by or endorsed by someone it is not — a lender, a regulator or a government agency. Impersonating an institution with a calculator is a way of lending false authority to a number.
• Alter a result and attribute the altered figure to this site, in a way that makes Rate & Sum appear to have produced a number it did not.

Note what is absent from that list, deliberately. Reading the page source, inspecting network requests, running the calculations against your own implementation and disagreeing publicly with a result are all explicitly fine — they are how anyone checks the arithmetic, and a site whose whole claim is that its maths is right has no business discouraging them. The privacy policy invites exactly that inspection and explains what you will find.

There is also nothing here to get access to that you do not already have. No accounts exist, so there are no credentials to guess; the calculators run in your browser, so there is no calculation endpoint to attack; and this build ships no administrative area at all. Everything a reader can reach is a static page that was built before they asked for it.

Every substantive claim about a rule, a threshold or a convention on this site links to the source it came from, and those links point at 16 domains outside our control. That is the point of citing them: you should be able to read the regulation rather than take our word for what it says. But it has two consequences worth stating plainly.

The first is that we do not control what is on the other end. A page can be rewritten, moved or withdrawn after we cite it, and a rule can change without the URL changing. Each citation records the date it was checked for that reason, so a stale source is visible as a date rather than hidden as an assumption. If you find one that has moved or now says something different, that is a defect worth reporting. The contact page says what makes such a report actionable.

The second is that a link is a citation, never an endorsement. Some of them point at federal agencies and regulators, and a few point at a commercial institution's own published explainer — used where that explainer is the clearest statement of a market convention, and cited for that reason alone. Linking to one says nothing about whether you should do business with it, and nothing about its rates, products or service. No arrangement of any kind exists between this site and any organisation it links to.

Links that arrive the other way are not ours to govern. Anyone may link to a page here, and no permission is needed. What we cannot do is control the wording around that link, so a third-party page presenting one of our estimates as a firm figure is not something this site has endorsed by being linked to.

The site is offered as it is, free, with no promise that it will be reachable at any particular moment and no undertaking to keep any page at its current address forever. There is no support arrangement and no service commitment, because there is no charge and nothing here holds anything of yours that could be lost. What is undertaken instead is narrower and checkable: a calculation found to be wrong gets corrected in the engine first, gains a test that would have caught it, and then every page that quoted the old figure is updated.

When this wording changes, the date on this page changes with it, and that date is what the sitemap publishes. There is no notification, because there is no mailing list and no account to notify — the date is the mechanism, and it is the same one every other page here uses. Earlier wording is not archived on the site, so the version you are reading is the one that applies.

Two clauses that nearly every terms page carries are absent from this one, and both are absent on purpose rather than by oversight:

1. No clause making you cover our costs. A free page with no accounts asking a reader to take on its legal expenses is boilerplate that got copied, and it would be no more meaningful here for being written in a confident tone. It is left out.
2. No governing law and no court named. Naming a state or a jurisdiction requires an entity with an address, and there is not one yet — this build does not even have its own domain configured. Inventing a venue would be fabricating the single most consequential fact in a document like this. It goes in when there is something true to put there, and the date above will move when it does.

What that leaves is the ordinary position, stated rather than dressed up: these are the terms on which a free reference site is offered, and where a term above is unenforceable in your jurisdiction, the rest of the page still describes how the site works. Nothing here limits any right you have that cannot be limited by a notice on a web page.