Terms of Use

These terms govern your use of rftools.io and everything on it — the calculators, the simulation tools, the reference data, the blog, the API and any account you hold (together, the Service).

By using the Service you accept these terms. If you do not accept them, do not use the Service.

If you create an account or start a paid subscription, you are told at that point that doing so accepts these terms and the Privacy Policy.

The Service is operated by an individual sole operator, identified with a postal address and a contact address at the head of this document. References to we, us and our mean that operator. References to you mean the person using the Service.

There is no company, and no other party is responsible for the Service.

You must be at least 16 years old to create an account. The Service is aimed at engineers and technical users and is not directed at children.

You are responsible for the credentials of any account you hold and for everything done through it. Keep your password and any API keys confidential. Tell us at the contact address if you believe an account or key has been compromised.

You may browse the calculators and reference content without an account. An account is required for saved calculations, simulation job history, API keys and paid features.

The Service offers a free tier and paid subscription tiers. What each tier includes, and its price, is described on the pricing page, which forms part of these terms.

Payments are processed by Lemon Squeezy, which acts as merchant of record for the paid tiers. Lemon Squeezy takes the payment, issues the receipt, handles applicable sales tax or VAT, and is the party your card statement will show. Their own terms and refund policy apply to the transaction in addition to these terms.

Cancellation. You may cancel at any time through the subscription management link Lemon Squeezy provides, or by writing to the contact address. On cancellation your subscription runs to the end of the period you have already paid for, and is not renewed. Access to paid features ends at that point. Refunds. We will refund a payment where we are required to by law, and will consider a refund request made within 14 days of a charge where the paid features have not been substantially used. Send refund requests to the contact address. Because Lemon Squeezy is merchant of record, a refund is issued through them. Price and plan changes. We may change prices or what a tier includes. A change to a tier you already subscribe to takes effect at your next renewal, and you will be told before it does. Continuing the subscription after that point accepts the change. Free tier. The free tier is provided at our discretion and its limits may change.

You may use the Service for your own engineering work, commercial or otherwise, including using its results in designs you build or sell.

You may not:

• access the Service by automated means except through the API, within the limits of your tier;
• scrape, crawl or bulk-download the calculators, content or reference data, or attempt to reconstruct the underlying dataset;
• resell, sublicense or redistribute the Service or its content as a competing product;
• share, publish or transfer an API key, or use one you were not issued;
• circumvent rate limits, quotas, tier restrictions, or any technical measure that enforces them;
• upload anything containing malware, or any file designed to disrupt the Service;
• upload material you have no right to disclose, including material subject to an obligation of confidentiality owed to someone else;
• probe, scan or test the security of the Service, or interfere with its operation or with other users' use of it;
• use the Service in a way that breaks any law that applies to you, including export control and sanctions law.

We may apply rate limits, quotas and other technical restrictions, and may change them.

API access is subject to the call quota and key limit of your tier, published on the pricing page. Quotas are counted per calendar month and reset at the start of each month.

An API key identifies your account. Requests made with your key are treated as made by you and count against your quota.

We may throttle, suspend or revoke a key that exceeds its quota, that is used in a way these terms prohibit, or that appears to have been disclosed.

The API is versioned and may change. We will avoid breaking changes to a published endpoint where we reasonably can, but we do not guarantee that any endpoint, parameter or response shape is permanent.

The Service — including the calculator implementations, simulation code, written content, worked examples, reference tables, design and branding — belongs to us or to our licensors, and is protected by copyright and other rights.

The underlying physics, mathematics and published models are not ours and are not claimed. Standard formulae, textbook methods and cited references remain freely usable; what is protected is our particular implementation, presentation and compilation of them.

What you may do with results. The numerical output of a calculation you run is yours. You may use it, publish it, and build hardware from it, without attribution and without a licence from us. What you may not do. You may not copy the content or code of the Service itself, or create a derivative service from it, without written permission.

Third-party names, standards and trade marks referred to on the Service belong to their owners and are used for identification only.

You may submit material to the Service — files uploaded for simulation, saved calculations, calculator requests, accuracy reports and any note attached to them.

You keep ownership of everything you submit. You grant us a non-exclusive, worldwide, royalty-free licence to store, process and display that material only so far as is needed to operate the Service for you — to run your simulation, show you your saved work, and act on a report or request you send.

You confirm that you have the right to submit what you submit, and that doing so does not breach a confidentiality obligation or anyone else's rights. Do not upload material you are not free to disclose.

A calculator request or accuracy report you submit may be published in a form visible to others. Do not put confidential information in one.

We may remove material that breaches these terms.

The Service is provided on an as-available basis. We do not promise any level of uptime, and there is no service level agreement.

We may change, suspend or discontinue any part of the Service, including a calculator, a simulation tool, an endpoint or a whole tier. Where a change materially reduces what a paid tier provides, we will tell subscribers before it takes effect.

Simulation jobs are queued and processed on shared capacity. Queue times vary, a job may fail, and a job that is interrupted — including by a deployment — may need to be resubmitted. Results of free-tier jobs are deleted automatically after 30 days.

You may stop using the Service at any time, and may ask us to delete your account by writing to the contact address.

We may suspend or terminate an account, an API key or access to the Service where these terms are breached, where required by law, or where continued access presents a risk to the Service or its users. Where we reasonably can, we will tell you why.

On termination, your right to use the Service ends. Data associated with your account is handled as described in the Privacy Policy.

Sections 7, 8, 11, 12, 13 and 16 survive termination.

The Service is provided "as is" and "as available", without warranty of any kind.

To the fullest extent permitted by law we disclaim all warranties, whether express, implied or statutory, including any implied warranty of merchantability, fitness for a particular purpose, accuracy, and non-infringement.

We do not warrant that the Service will be uninterrupted, secure or error-free, that results will be accurate or complete, or that any defect will be corrected.

Results are modelled approximations, not measurements. The calculators and simulation tools apply published models under stated assumptions. They are not a substitute for physical measurement, qualified engineering judgement, or regulatory testing and certification. This is set out in full in the Disclaimer, which forms part of these terms.

Nothing in this section limits any right you have as a consumer that cannot be excluded under the law that applies to you.

To the fullest extent permitted by law:

• We are not liable for any indirect, incidental, special, consequential, exemplary or punitive loss; nor for loss of profit, revenue, business, goodwill, anticipated saving, or data; nor for the cost of substitute services — in each case however caused, and whether or not we were told such loss was possible.
• We are not liable for any loss arising from hardware, firmware, systems or decisions derived from results the Service produced, including the cost of redesign, re-manufacture, rework, recall, retesting or recertification.
• Our total aggregate liability arising out of or relating to the Service, on any basis, is limited to the greater of the amount you paid us in the 12 months before the event giving rise to the claim, or 50 US dollars.

These limits apply to liability in contract, in tort including negligence, under statute and on any other basis.

Nothing in these terms excludes or limits liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for any other liability that cannot lawfully be excluded. If you are a consumer, your mandatory statutory rights are unaffected.

You will indemnify us against any claim, demand, loss, liability, cost or expense — including reasonable legal fees — brought by a third party and arising from:

• your use of the Service in breach of these terms or of any law;
• material you submitted to the Service, including any claim that it infringes a right or breaches a confidentiality obligation;
• your use of, or reliance on, results the Service produced, including in any product you designed, built, sold or certified.

We will tell you about any such claim and will not settle it without your agreement, which you will not unreasonably withhold.

The Service uses third parties to operate, and reproduces data from external sources. These include hosting and infrastructure providers, a payment provider, analytics, advertising and session-recording providers, and public data sources such as space-weather, satellite and spectrum-allocation feeds. They are named in the Privacy Policy and the Cookie Policy.

Data reproduced from an external source is provided as we received it. We do not warrant that it is current, complete or correct, and we are not responsible for the third party's own service, terms or availability.

The Service displays advertising. We are not responsible for advertisers or for what they link to.

We may change these terms. The effective date at the head of this document shows when the current version took effect, and previous versions remain retrievable from the project's version history.

Where a change materially affects your rights or obligations, we will give notice on the Service before it takes effect. Continuing to use the Service after that point accepts the changed terms. If you do not accept them, stop using the Service and, if you hold a subscription, cancel it.

These terms, and any dispute arising out of or in connection with them or with the Service, are governed by the law of Georgia, without regard to its conflict-of-laws rules.

The courts of Tbilisi, Georgia have exclusive jurisdiction, and you and we submit to that jurisdiction.

If you are a consumer resident in the European Union or the United Kingdom, this section does not deprive you of the protection of the mandatory consumer-protection law of your country of residence, or of the right to bring proceedings in the courts of that country where that law gives you it.

Before starting proceedings, please write to the contact address — most disputes are resolved that way.

Severability. If any provision of these terms is held unenforceable, the rest continues in force and the unenforceable provision is applied to the greatest extent permitted. No waiver. Failure to enforce a provision is not a waiver of it. Assignment. You may not assign your rights under these terms without our written consent. We may assign ours in connection with a transfer of the Service, on notice. Entire agreement. These terms, together with the Privacy Policy, the Cookie Policy and the Disclaimer, are the whole agreement between you and us about the Service, and replace any earlier understanding. Language. These terms are written in English. Translations are provided for convenience only; in the event of any discrepancy, the English text governs.

Write to the address at the head of this document, or email contact@rftools.io.

Please include enough detail to identify the account or the page concerned. We aim to reply within 30 days.