12 free seller tools for Shopify, Amazon, eBay and online stores
Calculate costs, contribution, returns, inventory, bundles, shipping and discounts. Draft product copy and inspect public product SEO signals for free, without registration.
Free · No registration · DE / ENCosts & profit
Marketplace Fee Calculator™
Commissions and additional charges often appear on different statements. This calculator uses your inputs on a stated net revenue basis.
Net revenue, platform and payment fees, variable costs, contribution and margin per sale.Open toolMargin & ROI Calculator™
Margin and markup have different denominators. ROI also needs invested capital and attributable net return; it cannot be inferred from margin alone.
Contribution per unit, margin, markup and optional totals and ROI from your inputs.Open toolProduct Price Calculator™
Adding a flat markup to sourcing cost misses percentage selling fees. The formula accounts for charges based on the future selling price.
Required price, expected contribution, actual margin after rounding and cost breakdown.Open toolBreak-even & Ad Cost Calculator™
A high ROAS alone does not establish profitability. This tool connects net revenue, variable costs, ad spend and orders on a consistent basis.
Contribution before and after ads, CPA, ROAS, break-even ROAS and optional required orders.Open toolReturns Cost Calculator™
Returns reverse sales and cause extra costs. An item write-down must not also be counted again as missing recovered stock value.
Expected returns, extra costs, refunds, cost per order and three rate scenarios.Open toolDiscount & Sale Price Calculator™
A lower price changes percentage fees while fixed costs remain. Reverse calculation shows a mathematical price floor.
Sale price, discount amount, contribution, margin and maximum calculated discount.Open toolLogistics & inventory
Inventory & Reorder Calculator™
Stockouts lose sales; excess stock ties up capital. Incoming stock counts only when its arrival is timely.
Available stock, reorder point, coverage, timely incoming units and reorder need.Open toolShipping Cost & Price Calculator™
A carrier rate alone can miss packing and handling. Weight, dimensions, provider and country document the scenario but do not supply a live tariff.
Shipping costs, net customer charge, gap, cost share and cost-covering net/gross amount.Open toolProduct Bundle Calculator™
A larger basket can contribute less after steep discounts or shipping. The calculation combines all entered items and quantities.
Individual selling value, bundle price, discount amount, product and total costs, and contribution.Open toolSEO & content
SEO Product Title Generator™
Vague or repetitive titles make products harder to understand. This generator arranges your supplied details without inventing attributes.
Product-first, keyword-first and benefit-or-feature-led drafts with character counts.Open toolProduct Description Generator™
Useful product copy explains real attributes. Templates use only supplied features, uses and benefits; uniqueness is not guaranteed.
Editable draft for the product page and search snippet, plus three questions based on your facts.Open toolProduct SEO Check™
Vague titles, missing product details and technical barriers make interpretation harder. Only retrieved evidence is scored.
HTTP and indexing signals, product attributes, structured data, evidenced findings and unknown checks.Open toolBeyond the calculator
If you need a hands-on SEO, GEO and conversion review, we can assess your store individually. The initial inquiry is free with no obligation; analysis starts at €45 before applicable tax.