Free core, paid operations
The WooCommerce plugin itself does not carry a subscription. The stack around it does: managed hosting, CDN, backups, security, paid extensions, theme work and someone to apply updates.
Those costs are easy to miss because they arrive on different invoices. The fixed-cost box adds them into one monthly number.
Fixed costs and variable costs
Hosting, plugins, maintenance and development amortization are fixed: they do not change with the next order. Payment processing and fulfillment are variable: they scale with order volume.
Operating cost per order is fixed ÷ orders + variable. COGS is tracked separately because it is a product cost, not a platform cost, but it is included in profit and break-even.
Worked example
500 orders, AOV $60, COGS $18, hosting $30, plugins $50, maintenance $100, theme/dev $20, payment 2.9% + $0.30, fulfillment $8.
Monthly fixed is $200, payment is $2.04 per order, variable is $10.04, fixed per order is $0.40 and operating cost per order is $10.44. Monthly profit is $15,780 and break-even is 7 orders.
Order volume changes the story
At 100 orders, the same $200 fixed cost is $2.00 per order and monthly profit is $2,996. At 500 orders it is $0.40 and $15,780. At 1,000 orders it is $0.20 and $31,760.
This is why a WooCommerce store with low volume can look expensive per order even when its software bill is small. The sensitivity table makes that visible.
WooCommerce vs Shopify cost structure
Shopify bundles hosting, security and core commerce into a subscription. WooCommerce separates them: you pay the host, the plugin vendors and the maintainer, and you own the operational work.
Payment processing and fulfillment exist in both. Compare the total stack, not the headline software price, and include the value of your time if you maintain the site yourself.
Where the model stops
It excludes taxes, refunds, ad spend, chargebacks, currency conversion, one-off migration costs and the cost of your own labor. Zero orders is allowed, but per-order fixed cost is undefined.
If contribution per order is zero or negative, more orders increase the loss. The break-even count is intentionally unavailable until price or variable cost changes.