I built 140+ free ecommerce calculators for marketplace sellers

I’ve been building EcomCalcTools, a free calculator hub for ecommerce and marketplace sellers.

The idea came from a simple but common problem: sellers often calculate profit as:

sale price - product cost = profit

But after marketplace commission, payment fees, shipping, ads, taxes, refunds, storage, and fulfillment costs, the real margin can be very different.

So I started building free calculators for different ecommerce scenarios:

- Amazon FBA fees and profit

- Etsy fees and digital download profit

- Shopify margins

- TikTok Shop fees

- Stripe vs PayPal fees

- Mercado Livre / Mercado Libre

- Noon

- Shopee

- Ozon

- Wildberries

- General ecommerce margin, markup, ROAS, break-even, and shipping calculators

The site is free and does not require signup:

https://ecomcalctools.com/

What I’m trying to validate now:

1. Which calculators sellers actually use repeatedly

2. Whether localized marketplace calculators are worth expanding

3. Whether bulk SKU import should become a Pro feature later

4. Whether ecommerce agencies would use this for client pricing checks

I’d appreciate feedback from anyone selling online or building tools for ecommerce sellers.

Would love feedback on which seller calculator is most useful or missing.