Terms of Service

These Terms of Service (the “Terms”) are a binding agreement between you and Limit State Software LLC, a Pennsylvania limited liability company based in Pittsburgh, Pennsylvania (“Limit State Software,” “we,” “us”), governing your use of CalcPackage — the website at calcpackage.com, the CalcPackage application, the free public calculators, and every related service we provide (together, the “Service”).

By creating an account, subscribing, or otherwise using the Service — including the free calculators, which require no account — you agree to these Terms and to our Privacy Policy. If you do not agree, do not use the Service.

If you use the Service on behalf of a firm or other organization, you represent that you have authority to bind that organization, and “you” includes it.

CalcPackage is a workspace for building, checking, and presenting engineering calculations. It renders live mathematical notation, tracks units, evaluates expressions, applies formulas and values transcribed from published engineering standards, provides AI-assisted drafting and explanation features, supports peer-review workflows, and exports calculation packages to PDF.

CalcPackage is a tool. It is not an engineering firm, does not provide professional engineering services, and does not review, certify, seal, or stamp any work. Section 3 is the most important section of these Terms — please actually read it.

The Service is built for licensed professional engineers, engineers in training, plan reviewers, and engineering students. It can make calculation work faster and more transparent. It does not replace professional engineering judgment, and using it creates no engineer–client relationship between you and Limit State Software.

When any output of the Service is used in work that affects life safety, property, or public welfare — and especially in any document that requires a professional engineer’s seal:

• The licensed engineer who seals or otherwise takes responsible charge of the work is solely responsible for its accuracy, applicability, and completeness.
• You must independently verify every calculation, assumption, code reference, and input value against the governing edition of the applicable standard and the requirements of your jurisdiction.
• Marking a block “verified” inside CalcPackage is an internal workflow marker. It is not a certification by us and does not transfer, share, or diminish the sealing engineer’s legal responsibility. The same is true of peer-review approvals recorded in the Service.
• AI-generated content is a starting point, never an authoritative output. It may cite the wrong provision, an outdated edition, or apply a formula outside its limits of applicability.

You will be asked to acknowledge these same responsibilities inside the application before you can author calculations. These Terms and that attestation are consistent by design; if you believe they conflict, these Terms control.

You must be at least 18 years old to create an account. You agree to provide accurate account information, keep it current, and protect your credentials. You are responsible for activity under your account. Authentication is provided by our identity provider (Clerk); we never see or store your password.

The free public calculators may be used without an account, subject to these Terms.

The Service includes AI features (such as generating worksheet scaffolds, explaining calculation steps, answering questions, and a research mode for standards outside our verified library). When you use them, the content you submit — typically your prompt and relevant worksheet content — is processed by our AI provider (currently OpenAI) to produce the response. Per our provider’s API terms, that content is not used to train their models. See the Privacy Policy for details.

• AI outputs may be incorrect, incomplete, or inapplicable to your situation. You must review and independently verify them before relying on them (see Section 3).
• AI usage is metered by plan. We may adjust quotas, model choices, and rate limits to keep the Service reliable and economical.
• AI features are never available to anonymous visitors on the public calculators.

The Service ships shape databases, material properties, and formula/value registries transcribed from published engineering standards (for example AISC, NDS, ACI, ASCE 7, and IBC references). We work to keep this data accurate and to version it so your worksheets record which registry edition they used. Nevertheless:

• The published standard governs. Where our data and the governing published edition differ, the published edition is correct and you must use it.
• You are responsible for confirming that the edition reflected in the Service is the edition adopted by your jurisdiction and applicable to your project.
• The standards themselves are the copyrighted works of their publishers. The Service transcribes numeric values and identifies provisions by citation; it does not reproduce the standards, and a subscription is not a license to any published standard.

You own your content. Worksheets, calculation packages, templates you author, custom libraries you upload, review comments, and uploaded images remain yours. You grant us a limited, non-exclusive license to host, store, process, display, and transmit that content solely to operate and provide the Service — for example: evaluating your calculations, rendering PDFs on our compute infrastructure, processing AI requests you initiate, showing shared worksheets to people you share them with, and keeping backups.

• Custom libraries and uploads. You are responsible for having the right to upload the data and files you upload. Do not upload proprietary databases or copyrighted tables you are not licensed to use this way.
• Share links. Worksheet share links are bearer links: anyone who has the URL can view the shared, read-only version until you revoke the link. Treat them accordingly.
• System templates and the Service’s own software, design, and content are ours or our licensors’ and are protected by intellectual-property law. We grant you a limited, non-transferable right to use them within the Service.
• Feedback you choose to send us may be used to improve the Service without obligation to you.

You agree not to:

• use the Service in violation of law or these Terms;
• circumvent plan limits, AI quotas, rate limits, or tier gating, or access another user’s content without authorization;
• probe, scan, or test the security of the Service without our prior written consent, or interfere with its operation;
• scrape, bulk-download, resell, or provide the Service (including the code-data registries) to third parties as a service;
• reverse engineer the Service except where that restriction is prohibited by law;
• misrepresent CalcPackage outputs as reviewed, certified, or sealed by Limit State Software.

We may suspend or terminate accounts that violate this section (Section 11).

The Service offers a Free plan and paid Pro subscriptions (monthly or annual), billed through Stripe. A Team plan is announced by waitlist and is not yet sold. By subscribing you authorize recurring charges to your payment method at the price shown at checkout, plus applicable taxes.

• Auto-renewal. Subscriptions renew automatically at the end of each billing period until cancelled.
• Cancellation. You can cancel anytime from the billing portal. Cancellation takes effect at the end of the current billing period; you keep Pro access until then.
• Refunds. Except where required by law, payments are non-refundable and we do not prorate partial periods.
• Downgrades. If a subscription ends or a renewal payment fails after our retries, your account moves to the Free plan. Your content is retained subject to Free-plan limits; Pro features (and clean, non-watermarked PDF export) become unavailable until you resubscribe.
• Price changes. We may change prices with at least 30 days’ notice; changes apply from your next renewal.
• Discount codes apply per their stated terms and may be modified or withdrawn prospectively.

Support staff cannot browse your worksheets. When you open a support ticket you may choose to attach a snapshot of a specific worksheet, grant time-limited live view access, or include a screen recording — each only with your explicit, per-ticket consent, used only to resolve your ticket, and logged in our audit trail. See the Privacy Policy for retention.

You may stop using the Service and delete your account at any time. We may suspend or terminate your access (with notice where practicable) if you materially violate these Terms, if required by law, or if we discontinue the Service. On account deletion your content is removed from production systems and expires from backups on the schedule described in the Privacy Policy. Sections that by their nature should survive termination (including Sections 3, 7, and 12–15) survive.

You are responsible for exporting what you need (worksheet PDFs and your data) before closing your account; we will honor reasonable export requests made within 30 days of closure.

THE SERVICE IS PROVIDED “AS IS” AND “AS AVAILABLE.” TO THE MAXIMUM EXTENT PERMITTED BY LAW, WE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, AND ANY WARRANTY THAT THE SERVICE, ITS CALCULATION RESULTS, ITS CODE-DATA REGISTRIES, OR ITS AI OUTPUTS WILL BE ACCURATE, COMPLETE, CURRENT, OR ERROR-FREE, OR THAT THE SERVICE WILL BE UNINTERRUPTED.

NOTHING IN THE SERVICE CONSTITUTES PROFESSIONAL ENGINEERING SERVICES OR PROFESSIONAL ADVICE. RESPONSIBILITY FOR ENGINEERING DECISIONS, AND FOR ANY WORK PRODUCT PREPARED WITH THE SERVICE, RESTS WITH THE RESPONSIBLE ENGINEER AS DESCRIBED IN SECTION 3.

TO THE MAXIMUM EXTENT PERMITTED BY LAW: (a) NEITHER LIMIT STATE SOFTWARE NOR ITS SUPPLIERS WILL BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, OR FOR LOST PROFITS, LOST DATA, OR COSTS OF SUBSTITUTE SERVICES, ARISING FROM OR RELATED TO THE SERVICE; AND (b) OUR TOTAL AGGREGATE LIABILITY FOR ALL CLAIMS ARISING FROM OR RELATED TO THE SERVICE WILL NOT EXCEED THE GREATER OF ONE HUNDRED U.S. DOLLARS (US $100) OR THE AMOUNTS YOU PAID US FOR THE SERVICE IN THE TWELVE (12) MONTHS BEFORE THE EVENT GIVING RISE TO THE CLAIM.

Some jurisdictions do not allow certain limitations, so parts of this section may not apply to you. This section reflects the allocation of risk on which the Service’s pricing is based: the professional responsibility for engineering work remains with the engineer (Section 3), not with a software subscription.

You will defend and indemnify Limit State Software against third-party claims arising from your engineering work product, your violation of these Terms, your violation of law, or content you upload without sufficient rights — except to the extent the claim results from our own breach of these Terms.

These Terms are governed by the laws of the Commonwealth of Pennsylvania, excluding its conflict-of-laws rules. The state and federal courts located in Allegheny County, Pennsylvania have exclusive jurisdiction over disputes arising from these Terms or the Service, and each party consents to personal jurisdiction and venue there.

Before filing a claim, you agree to contact us at support@calcpackage.com and give us 30 days to try to resolve the dispute informally.

The Service evolves — features may be added, changed, or retired. We may update these Terms; if a change is material we will give notice (by email to your account address or in-app) at least 14 days before it takes effect, except where a change is required sooner by law. Continued use after the effective date constitutes acceptance. The “Last updated” date above always reflects the current revision.

These Terms (with the Privacy Policy and any order/checkout terms) are the entire agreement between you and us regarding the Service. If a provision is unenforceable, the rest remains in effect. You may not assign these Terms without our consent; we may assign them in connection with a merger, acquisition, or sale of assets. Our failure to enforce a provision is not a waiver.

Questions? Contact support@calcpackage.com.