Built around the seller’s next decision
Should you increase ad spend? Is a new product worth stocking? What will a marketplace actually take from a sale? ShopMathLab exists to make those decisions easier with focused, free ecommerce calculators.
Small tools. Useful answers.
Our launch collection covers advertising, inventory, product costs and marketplace profit. Each tool combines an immediate result with a transparent formula and an example you can check yourself.
Free and private by design
No account is required. Calculations run in your browser, and raw financial inputs are not sent to a calculation server. We do not add fake reviews, usage counts or professional credentials to make a number look more trustworthy. The workings are available for you to inspect.