I built a privacy-first suite of 15 marketing & margin calculators (No signups, no data tracking)

Hey everyone,

Like most digital marketers, freelancers, and indie hackers here, I spend a lot of time calculating ROAS, e-commerce net profit margins, or checking CAC vs. LTV ratios.

What always annoyed me was trying to do a quick calculation online, only to find a tool that forces me to create an account, hands my email to a marketing sequence, or tracks my sensitive business metrics.

To solve my own frustration, I built FinCalcHub Marketing—a completely free, zero-signup platform with 15 essential business and marketing calculators.

Why I made it privacy-first:

• 100% Client-Side: Every calculation runs entirely inside your own browser. Your revenues, ad spends, and margins are never stored, tracked, or sent to a server.

• No Gatekeeping: No signups, no paywalls, and no usage limits. You open the page, get your numbers, and close it.

• Full Math Transparency: To build trust, every single calculator lists its exact formula alongside an example so you know exactly how the math works.

What you can calculate instantly:

• Growth Marketing: ROAS, Campaign ROI, CAC/LTV, and A/B Test Significance.

• E-Commerce Operations: Net Profit, Margin, and Markup metrics (accounting for platform fees and shipping costs).

• Freelance Analytics: Optimal hourly billable rates and strategic project planners.

I'd love for this community to try it out and give me some brutally honest feedback.

Question for the group: What is one specific financial or marketing formula you still calculate manually in Excel because you can't find a clean online tool for it? I'd love to build it next!