MerchantCalcs

Merchant decision tools for independent sellers

Business, e-commerce
& financial calculators.

Calculate profit, pricing, marketplace fees, advertising returns, loans, inventory and more with fast, transparent tools built for real business decisions.

Find your calculator How the math works
Merchant desk Ready
30Focused
calculators
Pricing & margin01
Ads & acquisition02
Inventory planning03
Freight & logistics04
Marketplace profit05

Inputs stay in this browser.

Calculator search

Find the right tool faster

New / Marketplace profit

Price the sale after the platform takes its share.

AmazonProfit calculator EtsyProfit calculator eBayProfit calculator ShopifyProfit calculator

01 / Popular tools

Start with the decision

Open the calculations sellers use most often. Browse a focused category below when you need something more specific.

02 / Categories

Browse by business question

Each collection groups calculators and guides that support the same decision, without duplicating calculator pages.

BusinessPricing, margin and break-even→ E-commerceProduct and store economics→ FinanceLoans, returns and cash decisions→ MarketingROAS, CAC, CPC and conversion→ MarketplacesAmazon, Etsy, eBay and Shopify→ OperationsInventory, freight and landed cost→

03 / Method

Visible math.
No black box.

Each calculator separates formula logic from page copy, validates unusual values and explains rounding. Changing marketplace fees stay editable.

01

Your inputs stay local

Calculations happen in your browser and are never submitted to our server.

02

Assumptions are shown

Every tool publishes its formula, variables, examples and limitations.

03

Rates are transparent and editable

Third-party fees can change. Applicable tools show dated sources and editable rates; verify account-specific pricing when needed.

04 / Blog

Latest seller research

New articles published from the MerchantCalcs editorial desk.

Retail pricing formula, selling price, margin and markupRetail Pricing Formula: How to Calculate Selling Price and MarginA practical retail pricing guide for sellers who need to turn unit cost into a workable selling price, compare margin with markup, account for selling fees and test discount headroom.Retail PricingRetail Calculator Guide: Price, Margin, Markup and ProfitLearn how to calculate retail price, gross margin, markup, unit profit and break-even sales with practical formulas and a worked product example.

05 / Field notes

Read before you decide

Focused explanations for pricing, inventory and shipping decisions.

Etsy seller profit Etsy Fees, Profit and Pricing: A Practical Seller Guide Build an Etsy price from real order economics instead of subtracting one headline fee from revenue. Customs and logistics HS Codes, Import Duty and Landed Cost for E-commerce Understand what an HS code can and cannot tell you before estimating customs duty, import tax and product landed cost. Pricing Margin vs. Markup: The Pricing Difference Sellers Must Know A practical explanation of why a 50% markup is not a 50% margin, with examples for small sellers. E-commerce How to Calculate True Profit per Order A step-by-step order profit method that includes product cost, shipping, ad spend, platform fees and returns. Finance Understanding Contribution Margin for Small Businesses Use contribution margin to decide which products, bundles or campaigns deserve more attention. Advertising How Break-Even ROAS Works Learn why a high ROAS can still lose money when margins are thin. E-commerce How Returns Affect E-commerce Profit Model refunds, reverse shipping and resale loss before a product looks healthier than it is. Inventory Reorder Point and Safety Stock Explained Avoid stockouts by combining demand, supplier lead time and a realistic buffer. Logistics Dimensional Weight Explained for Online Sellers Why large lightweight packages can be billed above their scale weight. Logistics Understanding Landed Cost Before You Import Bring freight, duties, insurance and handling into one per-unit cost. Pricing How Discounts Affect Profit Calculate how many extra units a discount must sell before it is worth running. Pricing Common Product Pricing Mistakes The quiet pricing errors that turn popular products into weak businesses.