What drives the cost
The screens are the cheap part. What drives an e-commerce budget is everything the customer never sees: inventory that stays accurate when two people buy the last item at once, tax and shipping calculated per US state and carrier, a payment flow that passes Apple and Google review, and order status that reconciles with whatever system your warehouse already runs on.
Teams that already sell on Shopify or BigCommerce can wire the app to that platform and skip most of the back end, which usually removes a meaningful slice of the estimate. Teams building their own commerce layer should expect the back end to be the largest single line in the breakdown.
The three e-commerce app scopes
Almost every project in this category lands in one of three scopes. Find yours here, then price it in the calculator.
MVP
1 – 2 months
The smallest version worth putting in front of real users.
Standard
4 – 6 months
A complete product with a custom back end and an admin console.
Advanced
11 – 14 months
Multi-role, real-time and built for national scale.
Where the money goes
The split below is the standard scope above, by share of the build. The calculator turns these shares into itemised dollar figures once it has your answers.
- UI/UX design6%
- Frontend development15%
- Backend development31%
- Features27%
- Infrastructure & DevOps5%
- QA & testing9%
- Project management7%
Cost factors specific to this category
- Catalog size and variants
- A hundred products with two options each is a very different data model from fifty thousand SKUs with size, colour and per-warehouse stock.
- Payments and wallets
- Card, Apple Pay and Google Pay is the US baseline. Buy-now-pay-later, stored cards and one-tap reorder each add integration and test surface.
- Tax, shipping and returns
- US sales tax is per-jurisdiction. Carrier rates, labels and returns are usually a third-party integration rather than something you build.
- Existing commerce platform
- Connecting to Shopify or an ERP shifts cost out of the back end and into integration work — normally a saving.
Recommended approach at standard scope
Cross-platform is the right default here
One shared codebase covers this scope comfortably, ships to both stores together and keeps ongoing maintenance with a single team.
A custom backend with a documented API
Your own API keeps business logic off the device, makes an admin console possible, and means a web app or partner integration later is an addition rather than a rewrite.
Cloud architecture proportional to your users
At 10,000–50,000 users a month, managed hosting with monitoring and backups is enough. Keep the infrastructure boring and spend the budget on the product.
Apps in this category
Used only as recognisable reference points for scope and complexity — no affiliation with, or endorsement by, these companies is implied. Products at this scale reflect years of iteration and operating spend that no initial build budget reproduces.
- Amazon
- Shein
- Etsy
Frequently asked questions
How much does it cost to build an e-commerce app?
It depends on scope, and the honest answer is a range you have to derive from your own requirements. In the US in 2026 an MVP of an e-commerce app takes 1 – 2 months. A standard build with a custom back end and an admin console takes 4 – 6 months. A scaled platform built for national volume takes 11 – 14 months. The calculator prices whichever of those shapes matches your project, itemised by discipline, in US dollars — answer seven questions and the full estimate is shown on screen and emailed to you.
Is it cheaper to build on Shopify than from scratch?
Almost always, for the first version. Using an existing commerce platform as the back end means catalog, inventory, tax, payments and order management already exist, and the project becomes a well-designed app plus an integration. Building your own commerce layer makes sense when your pricing, bundling or fulfilment rules cannot be expressed in someone else’s system.
Do I need an app if I already have a mobile-friendly store?
Only if repeat purchase is your model. Apps earn their cost through push notifications, saved payment details and one-tap reorder — all of which need returning customers. If most of your traffic buys once from search, the money is usually better spent on the mobile web experience.
What does an e-commerce app cost to run each month?
Budget separately for hosting, payment processing at roughly 2.9% plus 30 cents per US transaction, transactional email and SMS, image delivery, and the Apple and Google developer accounts. Most teams also allow 15–20% of the original build cost per year for maintenance, OS updates and small improvements.
Price your own scope
These are typical scopes, not yours. The calculator prices the exact features, platforms and traffic you have in mind, and shows the itemised breakdown behind the number.