Mobile app cost calculator
Work out a planning range using your own rate and scope. Every assumption is visible and editable.
Set your planning assumptions
Use your own rate. The effort ranges below are illustrative starting points you can edit.
The starting 1.2× multiplier is an editable cross-platform assumption. Use 1× as a single-platform baseline; adjust for your actual architecture.
Edit effort ranges
Your planning range
Development budget, including your contingency
Add your daily rate
25.2–49.2 person-days before contingency
- Work items included
- 4
- Platform multiplier
- 1.2×
- Contingency
- 20%
Method: sum included effort ranges × platform multiplier × your daily rate × (1 + contingency).
This is an editable planning model, not Derrick’s rates or a quote. Hosting, subscriptions, tax and ongoing support are not included. Person-days are effort, not a promised launch date.
Make the assumptions visible.
A useful estimate is something you can question. Adjust the effort for the core build, add the features you need and set a daily rate that belongs to your planning conversation. Nothing here is presented as a fixed package.
Scope the first useful release.
Accounts, payments and integrations can each change the work. Start with the job the app needs to do, then separate what makes that first release useful from what can follow later.
How to use it
Set your rate
Enter a daily rate and currency, or explicitly try the example. The calculator does not supply a rate on your behalf.
Adjust the scope
Choose additional features, edit the effort ranges and set your platform multiplier and contingency.
Compare and discuss
Copy the range and its assumptions. Use it to discuss scope, then validate the work before treating it as a budget commitment.
A worked example, with the inputs shown.
At an example £500/day, the default 21–41 days of core work, a 1.2× platform multiplier and 20% contingency produce a £15,120–£29,520 planning range. Change any input and the result changes. This example is arithmetic, not a quote.
From the first flow to a usable product.
I’m building Loytap, a beta loyalty app for independent coffee shops. The customer card, staff scanning flow and merchant dashboard each have their own jobs and requirements. That is the kind of scope a single headline price can hide.
App cost calculator questions
It adds the low and high effort estimates for the included work, applies your platform multiplier, multiplies by your daily rate and adds your contingency percentage. Every starting assumption is editable.
No. You supply the rate. The effort ranges and multiplier are illustrative planning inputs, not Derrick’s pricing, a market benchmark or a quote. A real scope needs a review of the product, integrations and delivery requirements.
The default model includes planning, interface design, a core build and testing/release. Add accounts, payments, an admin dashboard, an API integration, notifications or offline support as needed. Change the effort range for any item to fit your brief.
A range lets you make uncertainty visible. If a feature is poorly understood, its high estimate may need more room. Contingency adds a separate buffer; it does not make an uncertain scope fixed.
No. Person-days measure effort. Calendar time also depends on team size, parallel work, feedback, dependencies and release approvals.
The model excludes hosting, subscriptions, taxes, store-account fees, ongoing support and any work you have not included. Add those separately when planning a full product budget.
No. The calculation and copy controls run locally. Using the project enquiry link opens a separate contact form; it does not automatically send the estimate.
Turn the planning range into a clear scope.
Share the core job, who will use the app and what already exists. I can help shape a useful first release.