How to Start an Ecommerce Website: Checklist, Cost Items and Break-Even Math

What do you need to start an ecommerce website? (Short answer)

Opening an online store takes days today; ready-made platforms handle most of the design and checkout. The hard part is running it profitably and within the rules. So think of the requirements as five blocks and close each one before launch.

Below you'll find a checklist for each block, the cost items, and most importantly the math to do before you open: what one order leaves you and how many orders a month you need. The amounts are examples; replace them with your own quotes and rates.

• Legal base: business registration, terms of sale, returns and withdrawal policy, privacy and cookie policy, company details on the site
• Infrastructure: domain, ecommerce platform (hosted SaaS, open source or custom build), SSL, theme and mobile experience
• Payments: payment gateway, fees and installments, refund process
• Logistics: carrier contract (dimensional weight rates), packaging, stock or supplier setup
• Measurement and marketing: GA4, Search Console, UTM-tagged campaign links, a first ad test budget

Which legal steps come before launch?

Rules depend on your country, so treat this as a checklist to confirm with a local accountant or lawyer, not as legal advice. In most markets, selling regularly requires a registered business, and payment providers will ask for those details when you apply.

Consumer rules: show your terms of sale, delivery times, total price and returns policy before the customer confirms the order. In the EU, consumers can withdraw from most online purchases within 14 days without giving a reason, and Turkey applies the same 14-day period; some items, such as personalized products, are exempt. Faulty or wrong items must be accepted back regardless.

In Turkey specifically, sellers on their own website must register with ETBİS, the Ministry of Trade's e-commerce information system, before they start selling, and show a pre-information form and distance sales contract at checkout.

Data and messaging: publish a privacy policy and cookie notice (GDPR in the EU, KVKK in Turkey), collect explicit consent before sending marketing emails or texts, and keep a record of that consent. Add your legal business name and contact details to the site footer.

• Business registration (type and financial obligations: ask a local accountant)
• Local e-commerce registrations where required (e.g. ETBİS in Turkey, before selling)
• Terms of sale and pre-contract information shown at checkout with a consent box
• Returns and withdrawal page: period, exceptions, who pays return shipping
• Privacy policy and cookie notice
• Explicit consent and records for marketing messages
• Company details: legal name, registration number, address, email, phone

Hosted platform, open source or custom build?

Hosted platforms (SaaS stores) bundle hosting, security, payments and shipping integrations for a monthly fee and can be live in days. Open source options (for example WordPress + WooCommerce) carry no license fee, but hosting, updates and security become your or your developer's job. A custom build is the most flexible and the most expensive and slowest option; it only makes sense if you have a workflow ready-made systems can't handle.

Decide with three questions: how much monthly fixed cost can you carry, who will do the technical work, and which integrations are essential (marketplaces, carriers, accounting, ERP)? If first-year volume is uncertain, the option with lower fixed costs is almost always safer. Prices change often, so get more than one current quote and ask about transaction fees, paid add-ons and renewal terms.

What are the cost items of an ecommerce website?

Split costs into three groups. One-time setup items are paid once; monthly fixed costs are paid whether you sell or not; variable costs occur on every order. Most guides focus on the first two, but it's the third group that decides profit or loss.

When you build your own list, write 'who, how much, how often' for each item. Even if you'll do product photos, product copy and legal pages yourself, note the time; the founder's time is the biggest hidden cost of the first months.

• One-time: domain (renews yearly), theme/design, logo, product photography, product copy, legal pages, first stock, setup and integrations
• Monthly fixed: platform subscription or hosting, add-ons, bookkeeping, email/SMS tool, staff and storage if any
• Variable (per order): product cost, payment fee, shipping, packaging, return losses, ad cost

How much startup capital do you need? Formula and example

Instead of asking for a single number, calculate startup capital with a formula. Assume the store won't pay for itself in the first months and pick how many months you want to be able to last (your runway).

Example (illustrative amounts): setup items $3,000, first stock $6,000, monthly fixed costs $1,800 and a monthly ad test of $2,500. For a three-month runway: $3,000 + $6,000 + 3 × ($1,800 + $2,500) = $21,900. This ignores contribution from sales, so it's a worst-case buffer. If you work without stock (dropshipping), the stock line drops, but profit per order usually shrinks too.

• Startup capital = Setup + First stock + (Monthly fixed costs + Monthly ad test) × Runway (months)
• Runway: the number of months you want to last until sales cover fixed costs

How much does one order make? Contribution per order

This is the most important calculation to do before you open. Take an example order (illustrative amounts): order value $90, product cost $45, payment fee 3% ($2.70), shipping $7.50, packaging $1.50. A completed order leaves you $90 − $45 − $2.70 − $7.50 − $1.50 = $33.30.

Now add returns. If 8% of orders come back, the product returns to stock but outbound and return shipping plus packaging ($7.50 + $7.50 + $1.50 = $16.50) are lost. Expected contribution: 0.92 × $33.30 − 0.08 × $16.50 = $29.32. That's what each order leaves before advertising, and also the most you can pay in ads per order.

If your ad cost per order (CPA) is $18, net contribution falls to $29.32 − $18 = $11.32. Break-even ROAS follows: $90 / $29.32 = 3.07. Any ad dollar that brings in less than $3.07 of revenue loses money on that order. You can check this per product with the gross margin calculator and the ROAS calculator, and pin down shipping with the dimensional weight and shipping cost calculators.

• Completed-order contribution = Order value − Product cost − Payment fee − Shipping − Packaging
• Expected contribution = (1 − Return rate) × Completed contribution − Return rate × (Outbound + Return shipping + Packaging)
• Net contribution = Expected contribution − Ad cost per order (CPA)
• Break-even ROAS = Order value / Expected contribution

How many orders a month do you need? Break-even point

Monthly break-even orders = Monthly fixed costs / Net contribution per order. In the example, $1,800 / $11.32 ≈ 160 orders. Below 160 orders a month the store loses money; above it, it profits.

Methods that leave ad cost out of the unit math get $1,800 / $33.30 = 54.05, or 55 orders rounded up, for the same store. That's a threefold gap; for a store that sells through ads, a 55-order target can convince you you're profitable while you're losing money. Always calculate break-even on contribution after ads and returns.

Then reality-check it: 160 orders a month at a 1.5% conversion rate means about 10,700 sessions. Write down which channels will bring that traffic and at what cost before launch. Once you're measuring conversion rate, update the target with the conversion rate calculator.

We put every calculation in this guide (setup budget, monthly costs, contribution per order, break-even orders, runway and the site vs marketplace comparison) into a free Excel template that needs no sign-up. It's in Turkish, but the formulas work with any currency; download it from the resources section. It also includes a launch checklist.

• Monthly break-even orders = Monthly fixed costs / Net contribution
• Required sessions = Break-even orders / Conversion rate

Your own site or a marketplace? Same product, side by side

Imagine selling the same product on a marketplace with a 20% commission (an example rate; real commissions vary by category). The marketplace collects payment, so there's no payment fee: $90 − $45 − $18 − $7.50 − $1.50 = $18; with the same 8% returns, expected contribution is 0.92 × $18 − 0.08 × $16.50 = $15.24.

On your own site, $29.32 was left before ads. The gap is $29.32 − $15.24 ≈ $14. So in this example, unless your site's ad cost per order drops below about $14, the marketplace leaves more per order. At an $18 CPA, the site leaves $11.32 and the marketplace $15.24 (assuming no extra marketplace ads).

The site's advantage shows up over time: repeat customers, an email list and organic traffic bring orders without ad cost, average ad cost falls, and the customer data stays with you. In practice the usual answer is to run both: the marketplace for volume and cash flow, the site for repeat customers and brand. You can model the marketplace side per product with the marketplace profit calculator.

Technical and operations checklist

Before launch, verify every item with a test order: place an order with your own card, cancel it and refund it.

• Domain and SSL (https in the address bar), www and non-www redirect to one address
• Mobile checkout: only a few steps from cart to confirmation, guest checkout available
• Payments: installments if relevant, 3D Secure, failed payment and refund flows tested
• Shipping: dimensional weight and rates set correctly per product, free shipping threshold set from your profit math
• Product pages: original descriptions, size and material details, several photos, stock and delivery time
• Legal pages linked from checkout; consent to terms collected
• GA4 installed and the purchase event firing; Search Console verified and sitemap submitted
• Consistent UTM parameters on every campaign link
• Order, shipping and refund notification emails tested

What should you do in the first 30 days?

Launch day is just the start. The first month's goal isn't big sales; it's validating contribution per order and learning which channel brings orders at what cost.

• Week 1: test orders, feedback from first customers (friends and network), product page fixes
• Week 2: a small ad test (one channel, a few products); compare CPA with expected contribution ($29.32 in the example)
• Week 3: shift budget to best sellers, pull unprofitable products from ads, start collecting emails
• Week 4: redo the break-even math with actual return rate, shipping cost and CPA; set month two's budget accordingly
• Ongoing: watch which searches bring impressions in Search Console and strengthen category pages for them

6 common mistakes when starting an ecommerce website

Most of these can be prevented with the math you do before launch:

• Calculating profit without ads: compute break-even on contribution after ads and returns
• Copying a competitor's free shipping threshold: set it from your own order value and shipping cost
• Growing fixed costs from day one: expensive plans, add-ons and staff before volume is known
• Filling product pages with supplier copy: it's hard to stand out in search among hundreds of pages with the same text
• Leaving measurement for later: if GA4 and UTMs aren't set up at launch, the first month's data never comes back
• Copying legal pages: another store's terms don't reflect your returns policy or products