Privacy Policy

Concrete Form Calculator Operated by Appco LLC, DBA Concrete Form Calculator

Effective Date: June 9, 2026 Last Updated: June 9, 2026

1. Introduction

Concrete Form Calculator ("we," "us," or "our") is operated by Appco LLC, a Wisconsin limited liability company doing business as Concrete Form Calculator. This Privacy Policy describes what information we collect when you use concreteformcalc.com (the "Service"), how we use it, who we share it with, and your rights regarding your information.

By creating an account or using the Service, you agree to the practices described in this Privacy Policy.

2. Information We Collect

2.1 Account Information

When you create an account, we collect:

• First and last name, required at signup
• Email address, required for authentication and account identification
• Company name, optional and provided at your discretion
• Password, stored in hashed form by our authentication provider, Supabase; we do not have access to your plaintext password

2.2 Calculation Data

When you run a calculation using the Service, we log the following to our database:

• The inputs you submitted (tank diameter, wall thickness, arc angle, mid ordinate maximum, and interior panel size selection)
• A summary of the calculation result
• The number of credits deducted and your remaining credit balance after the calculation
• A timestamp of when the calculation was performed

This data is stored in association with your account and is accessible to you through your account history. We use it to maintain an accurate credit ledger and to support any billing disputes or error investigations.

2.3 Payment and Transaction Data

Payments are processed by Stripe, Inc. We do not collect or store your credit card number, card verification code, or full card details. Stripe handles all payment processing directly.

We do store:

• Stripe Checkout Session IDs and Stripe Payment Intent IDs, used to confirm and reconcile purchases
• The credit pack you purchased and the price paid
• Timestamps of purchase events

For Stripe's privacy practices, see https://stripe.com/privacy.

2.4 Usage and Server Data

Our hosting infrastructure (Vercel) and our authentication/database provider (Supabase) may collect standard server-level data in connection with your use of the Service, including:

• IP addresses
• Browser type and version
• Referring URLs
• Request timestamps and HTTP request logs

This data is collected as part of normal server operations and is subject to the privacy policies of Vercel and Supabase (see Section 4 below).

3. How We Use Your Information

We use the information we collect to:

• Create and maintain your account
• Authenticate your identity and secure your session
• Process credit purchases and maintain your credit balance
• Run calculations and deliver results, PDFs, and CSV exports to you
• Attribute exported reports to your account (your email address appears in PDF report footers as a watermark)
• Investigate errors, support billing disputes, and provide customer support
• Maintain accurate transaction records for accounting and fraud prevention
• Comply with legal obligations

We do not sell your personal information. We do not use your information for advertising or share it with advertising networks.

4. Third-Party Service Providers

We rely on the following third-party providers to operate the Service. Each provider acts as a data processor and is subject to its own privacy policy.

We do not share your personal information with any other third parties except as required by law or to enforce our Terms of Service.

5. Data Retention

We retain your account information and transaction history for as long as your account is active. If you request account deletion, we will delete your account and associated data from our production systems. Some data may persist in database backups for a limited period following deletion.

Calculation input logs and transaction records may be retained for a reasonable period after account deletion for accounting, fraud prevention, and legal compliance purposes.

6. Email Communications

6.1 Transactional Emails

We will send you emails that are necessary to operate your account and deliver the Service. These include purchase receipts, credit balance notifications, account verification, password reset, and other service-related communications. Because these emails are required for account operation, you cannot opt out of them while maintaining an active account.

6.2 Promotional Emails

By creating an account, you agree that we may send you promotional emails about new calculators, feature updates, credit pack offers, and other news related to Concrete Form Calculator. You may opt out of promotional emails at any time by clicking the unsubscribe link included in any promotional email. Opting out of promotional emails does not affect the delivery of transactional or account-related emails.

6.3 No Sale of Your Information

We will never sell, rent, or trade your personal information (including your email address) to any third party for their marketing purposes.

7. Your Rights

You may access your account information and transaction history by logging into your account. If you wish to correct, update, or delete your account information, or if you have any questions about the data we hold about you, contact us at contact@concreteformcalc.com.

We will respond to data requests within a reasonable timeframe. We may need to verify your identity before acting on a request.

8. Security

We take reasonable technical and organizational measures to protect your information, including:

• All data is transmitted over HTTPS/TLS
• Authentication is managed by Supabase, which provides secure session management
• Database access is controlled by row-level security policies that restrict each user to their own data
• Credit balances and transaction records are read-only to browser clients; they can only be modified by server-side code using privileged service credentials

No method of transmission over the internet is completely secure. We cannot guarantee absolute security, but we are committed to protecting your information using industry-standard practices.

9. Children's Privacy

The Service is intended for use by businesses and professionals in the construction industry. We do not knowingly collect personal information from individuals under the age of 18. If you believe we have inadvertently collected information from a minor, contact us at contact@concreteformcalc.com and we will promptly delete it.

10. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. If we make material changes, we will update the "Last Updated" date at the top of this page and, where appropriate, notify you by email. Your continued use of the Service after any changes constitutes your acceptance of the updated policy.

11. Contact Us

For questions, concerns, or data requests related to this Privacy Policy, contact us at:

Appco LLC, DBA Concrete Form Calculator contact@concreteformcalc.com concreteformcalc.com