Marketplaces
2 toolsCalculate real profit after each platform’s specific fees and costs.
Browse this category →Work out what your ecommerce really earns
See what you keep per sale, how much you can spend on advertising, and what fees, tax and returns are really doing to your margin.
Free
No sign-up
Runs in your browser
Formulas in the open
20 tools · 6 categories
Find the calculator for the decision you need to make
Choose the area of your business you want to review. Each category brings together tools that share data and decisions.
Profitability
2 toolsMeasure how much each sale contributes and compare which channel adds more profit.
Browse this category →Marketing and acquisition
3 toolsDecide how much you can spend to acquire customers and when that investment pays back.
Browse this category →Pricing and promotions
5 toolsSet prices, discounts, bundles and shipping thresholds without destroying margin.
Browse this category →Inventory
5 toolsDecide how much to order, when to reorder and what it costs to hold or run out of stock.
Browse this category →Operations and cash flow
3 toolsControl imports, returns and how long your cash remains tied up.
Browse this category →International
Eight markets, five currencies, two languages
Interface language and calculation market are independent. Read the site in English and calculate with euro fees and German VAT; or read it in Spanish and calculate in US dollars. The market sets the currency, the tax and the Etsy and Amazon fees; the language only sets the words.
Changing currency changes the unit, it does not convert the amounts: this tool applies no exchange rate.
Market
- Spain (ES) · EUR · VAT 21%
- United States (US) · USD · sales tax
- United Kingdom (GB) · GBP · VAT 20%
- France (FR) · EUR · VAT 20%
- Germany (DE) · EUR · VAT 19%
- Italy (IT) · EUR · VAT 22%
- Canada (CA) · CAD · GST/HST 5%
- Australia (AU) · AUD · GST 10%
Recommended path
The order that actually makes sense
First work out what each sale leaves you; then add what inventory, returns and cash take out of it; and only then decide prices and how much you can spend to win customers. You do not have to go through it all: if the earlier stages are already clear, start wherever you need to.
Work out what each sale leaves you
Strip out tax, product, logistics and fees to see what you actually keep, whether you sell from your own store or on a platform. This is the foundation for everything else.
Add inventory, returns and cash
That margin is not clean yet: it is missing what it costs to hold stock, to run out of it, to handle a return, and the time your money spends tied up.
Decide pricing and acquisition
With a corrected margin, set discounts, bundles and shipping thresholds without destroying it, and work out how much you can pay for a customer and when you get it back.
How it works
Three steps and you are done
1. Pick your market
The selector at the start of each calculator loads the currency, tax and fees for wherever you sell: Spain, the United States, the United Kingdom, France, Germany, Italy, Canada or Australia.
2. Type your numbers
Price, costs, fees and, if you want, the advanced options. Either decimal mark works, and every field explains what to put in it.
3. Read the interpretation
Beyond the figures, each calculator tells you in plain language what they mean and what is worth checking, with the full breakdown if you want to verify it.
Guides
Guide
How to calculate ecommerce profitability
From gross revenue to real profit: tax, product, logistics, gateways, advertising, returns and fixed costs.Reviewed on August 21, 2026Read the guide →GuideROAS, ACoS, CPA and CPC: differences and formulas
Four metrics measuring the same thing from different angles, with the formulas, the conversions and the usual mistakes.Reviewed on August 21, 2026Read the guide →GuideThe real cost of returns in ecommerce
The lost sale, reverse logistics, the fees that do not come back and the provision you should be setting aside per order.Reviewed on September 12, 2026Read the guide →GuideEtsy fees by country: a comparison
The fees Etsy applies to an order, what base each one uses, and how they differ across the eight markets.Reviewed on August 21, 2026Read the guide →GuideAmazon FBA fees by market: a comparison
Selling plans per marketplace, referral fee, fulfillment fee, storage, inbound shipping and advertising.Reviewed on August 21, 2026Read the guide →GuideCompare sales channels: own store, Amazon and Etsy
You sell the same product in more than one place and you are not sure which one actually pays you.Reviewed on September 12, 2026Read the guide →GuideHow to plan ecommerce inventory
You buy stock on instinct and you alternate between running out and filling the warehouse with what will not sell.Reviewed on September 12, 2026Read the guide →GuideCAC, payback and margin: how much to spend
You spend on advertising, you see a ROAS that looks fine, and you cannot tell whether the business is getting better or worse.Reviewed on September 12, 2026Read the guide →GuideNegotiate MOQ without straining cash flow
Your supplier is asking for a minimum order that looks large and you cannot tell whether to accept it, negotiate it or walk away.Reviewed on September 12, 2026Read the guide →Case studies
Hypothetical businesses worked end to end with Profyza's calculators: the starting figures, the order of calculation, the scenarios and the decision the numbers point to.
Case study · Diagnose the business
Why a store makes €30,000 in revenue but no profit
The decision: Whether the problem is the campaigns or the cost structure, and which lever to pull first.
Method: 5 tools · 3 scenarios
Calculators it uses: Contribution margin · Minimum price · Maximum CAC · Cost of returns · Break-even ROAS
Case study · Decide the inventory
Safety stock or tied-up cash: which costs more?
The decision: What cycle service level to set for this product.
Method: 4 tools · 3 scenarios
Calculators it uses: Safety stock · Reorder point · Inventory carrying cost · Stockout cost
Case study · Decide the budget
When to stop scaling campaigns: profit and cash
The decision: How far to raise spend, and which signal to watch when deciding.
Method: 4 tools · 3 scenarios
Calculators it uses: Contribution margin · Maximum CAC · CAC payback · Break-even ROAS
Methodology
How we calculate, no black boxes
Every result on this site can be reproduced by hand. The formulas are published on each calculator page, the tax treatment is explained, and the Etsy and Amazon fees carry their official source, review date and verification status.
We work with the contribution margin: tax-exclusive revenue minus every cost that grows with each order. That is the figure that can actually pay for advertising. Fixed costs are covered by the sum of the month's margins, which is why your targets should sit above break-even.
What the calculations do and do not include
Included:
- Tax, configurable per market
- Product and material costs
- Shipping, packaging and fulfillment
- Gateway and platform fees
- Advertising attributed to the order
- Returns provision
Not included:
- Fixed costs (rent, salaries, software)
- Taxes on profit
- Depreciation and financing
- Tied-up stock and obsolescence
Frequently asked questions
Are the calculators really free?
Yes. No sign-up, no account, no usage limit and no hidden paid tier. The project will be funded by advertising, not by charging for the tools.
Do you store my financial figures?
No. Every calculation runs in your browser. The numbers you type never travel to a server, are never written to a database and disappear when you reload. The only thing stored in your browser is the market code you picked — two letters — so you do not have to select it again.
Can I use the English interface with the Spanish market?
Yes, and that is one of the reasons this version exists. Language and market are independent: either language works with any of the eight markets and their five currencies.
Does it convert the amounts when I change currency?
No, deliberately. Changing market changes the currency unit, the tax and the fees, but applies no exchange rate: there is no currency API behind it. To compare markets, enter the real figures for each one.
Which markets and currencies are covered?
Eight markets — Spain, the United States, the United Kingdom, France, Germany, Italy, Canada and Australia — and five currencies: euro, US dollar, pound sterling, Canadian dollar and Australian dollar. Each market brings its own tax, Etsy fees, Amazon plans and example values.
How reliable are the results?
The formulas are published on every page and the calculation engine is covered by an automated test suite that also checks all eight markets and five currencies. That said, they are estimates: they depend on what you enter and on the fees matching your real invoices.
Are the Etsy and Amazon fees verified?
Every fee carries its official source, its review date and its verification status: verified, derived from a verified sibling figure, or pending verification. Where a source could not be consulted we say so rather than presenting the number as confirmed. And any value you edit always overrides the preset.
Is this project connected to Etsy or Amazon?
Not at all. It is an independent project, not affiliated with, sponsored by or endorsed by Etsy, Amazon or any other platform. Their names appear only to identify whose fees are being modelled.
Independent project. Independent project. Not affiliated with, sponsored by or endorsed by Etsy, Amazon, Shopify, WooCommerce or Google. The preloaded fees are editable reference values: always compare them with your real invoices. Results are estimates based on the information you enter. Fees, taxes and platform terms can change: always check the figure that matters to you against your invoice or the official platform. They do not replace your real invoices, your official accounts or professional tax, financial or legal advice.