Know your numbers.
Make your
next move.
Model product profit, marketplace fees, ad performance, and inventory before you commit cash. Free tools, clear assumptions, and answers you can put to work.
Make $2.50 for every $1 you spend on ads.
More growing.
For the way you sell
Big decisions. Simple math.
From your first sale to your next big restock, we’ve got the math covered.
Break-even ROAS
Find the ROAS you need to break even, including product cost, fees, shipping, discounts and returns — not just revenue.
Amazon FBA fees & profit
Get a clear picture of product profit after Amazon fees, fulfillment and ads.
Customer acquisition cost
Understand what it really costs to win a new customer, beyond your ad spend.
Reorder point
Know exactly when to restock so your next best seller never goes out of stock.
Inventory turnover
See how efficiently your inventory is moving and how long your stock lasts.
Landed cost
Uncover the true cost of getting a product from your supplier to your shelf.
Inventory carrying cost
Put a number on the hidden cost of holding inventory, from storage to capital.
eBay seller fees
See your eBay fees, take-home profit and margin before you list.
Etsy seller fees
Factor in listing, transaction and payment fees to price your handmade work.
Shopify order profit
Find your true order profit after payment fees, shipping, discounts and ads.
Built on formulas.
Not guesswork.
Behind every result is a clear formula, honest assumptions, and an explanation you can actually use.
Explore our methodologySee the workings
Clear formulas and real examples. Understand the how, not just the answer.
Sources, not secrets
Marketplace fee references and editable rates keep assumptions in plain sight.
Your business stays yours
Your calculations happen in your browser. No account. No financial data collected.
US marketplace fee references checked September 18, 2026.
Beyond the calculator.
Practical reads for more profitable decisions.
Your ROAS looks good. But are you actually profitable?
Go beyond the ad dashboard and find the number that really matters.
FBA profit is thinner than the sale price suggests.
Referral fees, FBA fulfillment, storage and the break-even price behind every listing.
Revenue is a start. Know what you actually keep.
Meet contribution margin: the missing piece in your product economics.
Your next good decision starts here.
Pick a calculator. Put in your numbers. Find your way forward.