Privacy and Tool Use Terms

This page describes the local calculator and worksheet functions, including files you choose to save. It also states the limits of the planning results. A calculation is not a physical measurement or a guarantee of a finished build.

Calculator inputs stay in the browser

The calculator processes measurements on your device. Calculate does not submit a measurement form to a server. Entries remain available while the page is open; leaving or reloading it can clear them unless you save a local plan.

The local save action creates a JSON file through your browser. Import reads a file you choose on your device. These files can contain model identifiers, sizes and assumptions. Review a file before sharing it through another service. No public saved-plan URL is created.

Printing and correction worksheets

Printing uses your browser's print dialog. A PDF destination, if available, is supplied by the browser or operating system. Check the destination before saving or printing, especially on a shared device.

The optional correction worksheet lets you copy or download a report locally. Those actions do not submit it. Do not include unnecessary personal or vehicle data in a report you intend to share elsewhere.

Messages you choose to send

The contact form sends your email address, optional name and subject, and message to this site's delivery service. The service adds a country code and submission time. Your IP address is used for spam rate limits; it is not included in the message sent to the publisher. The form uses a hidden spam field and a signed fill-time check, and rejects web links and common spam phrases.

Accepted messages enter a private delivery queue for up to 90 days and are removed from that queue after the mail server accepts delivery. The publisher's receiving mailbox retains the correspondence so we can answer questions and investigate corrections; no fixed mailbox-retention period is stated here. We use these messages to handle your request, not to add you to a mailing list. Calculator inputs and saved plans are sent only if you choose to include them in your message.

Outside sources and links

Following a source link opens a different website with its own policies and server records. The cited manuals and technical pages are outside resources. Your browser makes a network request when you visit them; the local calculator does not upload your saved plan along with that link.

No advertising service, marketing signup or Google Analytics ID is configured in this build. The site's consent helper requests a country and region from its own /api/geo address. Where a consent choice is shown, it can store that choice in your browser under site-consent.

The product roundups contain Amazon affiliate links. We may earn a commission from qualifying purchases made through them, as explained in our affiliate disclosure. Following one opens Amazon, where Amazon's own privacy and cookie policies apply. Calculator inputs and saved plans are not sent with the link.

The site's offer-click helper sends the page path and offer label to its own /api/click address when you click a sponsored product link, including a linked product name, image or View on Amazon button. If the landing URL has utm_source, utm_medium, utm_campaign or utm_content labels, the helper keeps them in tab storage under click-utm and includes them with later offer clicks. This measurement runs even if analytics consent is declined. The server handler records those fields with a country code and time. Calculator inputs and saved plans are not part of that payload.

Hosting request logs, browser extensions and services you choose to use have their own data handling. No fixed hosting-log retention period is stated here because the hosting setup has not been verified.

Your choices

You can remove site-consent from local storage and click-utm from session storage using your browser's site-data controls. Closing the tab clears its session storage. Clearing site data does not delete JSON files or printed PDFs that you saved yourself; remove those files on your device if needed.

Tool use terms

Use a result as a planning calculation under its stated assumptions. Verify the exact driver model, manual revision and real sizes before cutting or installing parts. Unknown inputs mean the related result or fit check is incomplete.

Net volume, acoustic tuning and physical fit are separate checks. The tools do not prove sound quality, maximum power, port noise, material strength or vehicle attachment. Use the actual product, tool and vehicle instructions for those tasks.

Keep local copies of the source identity and formula version when relying on a plan. Calculate again after changing thickness, braces, driver count or a vent. Prepare a suspected-error report with its inputs in the local correction worksheet. Read About for the source-checking method.