Free tools for online sellers
Free calculators for Shopify, Etsy and Amazon sellers: profit & ROAS, marketplace fees, discounts, dimensional weight and AI prompts.
Profit & break-even ROAS
True margin after fees, shipping, ads and FX.
Shopify / Etsy / Amazon fees
What each marketplace takes per sale.
Product description prompts
Copyable AI prompts for better listings.
Discount & markup
Price smart, discount without losing money.
Dimensional weight
Billable shipping weight in seconds.
How to use
- Pick a tool.
- Enter your numbers — everything runs privately in your browser.
FAQ
Are the tools free?
Yes, all free with no signup.
Is my data stored?
No. Calculations happen locally in your browser.