Ecommerce Fees Calculator: What Every Store Builder Costs You

An ecommerce fees calculator is only as honest as its inputs, so here are ours, itemized. Every figure the tool prints comes from the same verified rate table as our written reviews — vendor fee schedules checked in August 2026, re-verified when vendors reprice — and every total it produces can be reproduced by hand with the formula below. No estimates dressed as facts; where we assume, we label the assumption.

How the math works

One formula per builder: monthly cost = plan fee + (revenue × processing %) + (orders × fixed fee per order) + (revenue × platform %). Four entries, nothing hidden. The plan fee is the builder's cheapest real-store plan at annual billing. Processing is the builder's own or default gateway at US standard-card rates — a percentage of revenue plus fixed cents per order, which is why order count matters as much as revenue: forty $50 orders pay $12.00 in fixed fees where four $500 orders pay $1.20, on identical volume. The platform percentage is the surcharge a few builders add on top of processing; for most of the table it is zero, and the exceptions are the interesting part.

What the total includes — and what it leaves out

Included: plan fee, processing, platform surcharge — the unavoidable cost of taking money. Excluded, deliberately: apps (a realistic $50–$150 a month on a typical Shopify stack), premium themes (roughly $100–$400 one-time on Shopify, $49–$149 a year on WooCommerce), shipping and label costs, email beyond free tiers, and domains ($12–$20 a year). Those vary too much by store to average honestly, so the calculator prices the part that does not vary. One labeled assumption: WooCommerce has no plan fee, so we book $15 a month of hosting as its stand-in — adjust mentally if yours runs more.

Why the rates differ

Three 2026 changes drive most of the spread. Square raised its Free plan's online rate to 3.3% + $0.30 on January 13, 2026 (Plus and Premium pay 2.9% + $0.30) — the price of a $0 plan fee is the worst processing line in the table. Squarespace's Basic plan carries a 2% platform fee on physical sales that the $10-dearer Core plan removes, which is how Basic manages to be the cheapest plan and the most expensive builder at the same time. And BigCommerce's June 2026 restructure made its famous 0% conditional: process outside its roughly 21 approved embedded gateways and an open-gateway fee of 2% (Core), 1% (Growth), or 0.6% (Scale) posts on every sale — the same shape as Shopify's 2%/1%/0.6% surcharge for declining Shopify Payments. The calculator assumes each builder's own or default gateway; stray from it and your real bill grows.

Reading the results: effective take rate

Each row carries two numbers. The monthly total is self-explanatory. The effective take rate is that total divided by your revenue — the true percentage of sales the builder keeps. It is the honest comparator because it folds fixed costs into the percentage: a $29 plan fee is 2.9 points of take at $1,000 a month but only 0.29 points at $10,000, which is why the rows reorder as you move the sliders. Watch for the crossovers: Square Online Free tends to hold the cheapest line below roughly $1,500 a month (no plan fee to amortize), and WooCommerce takes over above it (no cost that scales with revenue).

A worked example

Set $2,000 a month and 40 orders — a $50 average order — and take the Shopify Basic row: $29 plan + $58.00 processing (2.9% of $2,000) + $12.00 fixed fees (40 × $0.30) = $99.00 a month, an effective take rate of 4.95%. Run every builder at that volume and the ledger reads: Square Online Free $78.00, WooCommerce $85.00, Shopify Basic / Wix Core / Squarespace Core $99.00 each, BigCommerce Core $100.40, Squarespace Basic $129.00. Every total reproduces by hand from the formula above — which is the point of publishing the formula.

For the verdicts behind the numbers, see the ranked ledger of the best ecommerce website builders; for the rates alone, transaction fees compared gives every builder one row and no adjectives.