Free tool
What would your software cost to build?
Tell us what you are building, what it needs to do and what it has to talk to. You get a costed estimate, a timeline and a list of what is included, in about three minutes. It is a guide to work from rather than a quote, and a real price needs a proper scoping conversation.
Step 1 of 6
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What kind of business are you?
It sets the language, the suggestions and the systems we expect you to be running.
Who is going to use it?
This changes what we ask next, and whether we can work out a return for you.
Where does it need to run?
Pick everything that applies.
What does it need to do?
Pick everything that applies. You can be generous; we phase the build so the first release is useful on its own.
What does it need to talk to?
Integrations are one of the biggest things that move a price, and most estimates leave them out. Pick the ones you use. If it is not listed, tell us and we will price the discovery work in.
A few last things
These change the effort more than most people expect.
What does this work cost you today?
Only so we can work out what the system pays back. Best guesses are fine, and you can skip it.
Across what you picked
0 hours a week
Your estimate
A PDF with every answer and figure. Just your email, and no call unless you ask for one.
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Build cost
Timeline
Running / month
Payback
This is a guide, not a quote.
The figures come from your answers and our engineering day rate. A real price needs someone to look at your systems, your data and how you actually work, and it can come out higher than this. Undocumented systems, awkward integrations, regulatory requirements and data that needs cleaning before anyone can use it all add days. Treat this as the starting point for a conversation, and the number we put in writing after scoping as the one that counts.
What that includes
Everything below is inside the figure. Nothing here is an extra.
Your next step
Talk this through with the engineer who would build it
Thirty minutes with the engineer who would build it. We will have read your answers before we ring, and we will say plainly if something is not worth doing.
Rather pick a time yourself? Choose a slot in the calendar
Wondering whether AI agents could do some of this work instead of a new system? Try the AI agent cost calculator.
A guide, not a quotation. Estimates are built from the answers you give and can come out higher once the work is scoped properly. For the day rate and the bands behind these numbers, read what custom software costs in the UK. For how we scope and build, see custom software.
What an app costs to build in the UK
This calculator prices an app the way we do. Each area of work has a band of engineering days, the days are added up, and the total is multiplied by our rate of £800 a day, which is £100 an hour. Once the work is scoped we quote it as a fixed price for each phase, so the number you sign is the number you pay for that phase.
Logins, an admin back office and design and testing are added to every estimate automatically, because we would not hand over a system without them. A mobile app also carries the server behind it. The smallest web app for your own team, covering one job, comes to about £16,000.
The day bands behind the numbers
| Area of work | Days | At £800 a day |
|---|---|---|
| Marketplace or multi-vendor | 8 to 18 | £6,400 to £14,400 |
| Jobs, or scheduling and dispatch | 6 to 14 | £4,800 to £11,200 |
| Quoting, stock, or booking and ordering | 5 to 12 | £4,000 to £9,600 |
| Customer records, reporting, invoicing, content | 4 to 10 | £3,200 to £8,000 |
| Documents, compliance, payments, messaging | 4 to 9 | £3,200 to £7,200 |
| Timesheets, maps, profiles | 3 to 8 | £2,400 to £6,400 |
| Approvals and workflow | 3 to 7 | £2,400 to £5,600 |
Each area after the first is counted at 90 per cent, because the second and third share the groundwork laid by the first. A named integration such as Xero or Stripe adds 1.5 to 3 days. Mobile adds about 15 per cent over web, and a web app with a mobile app adds about 30 per cent.
Two examples, run through the calculator
A system for your own team
A trades business wants one web app for jobs, scheduling and invoicing, linked to Xero, for up to 20 staff. It holds customer details and replaces a set of spreadsheets. The calculator puts that at about 49 engineering days, which is £39,500, over about 12 weeks, then £95 a month to host.
Say the team spends 46 hours a week between them on that work today, on salaries of about £30,000. The calculator counts only 60 per cent of that time as won back, and even then the system pays for itself in about 20 months and is about £34,000 ahead after three years.
An app for your customers
A booking app on iPhone and Android, with card payments through Stripe, messages and notifications, for a few thousand customers. With the server behind it, accounts, an admin back office and data protection work, the calculator puts it at about 74 days, which is £59,000, over about 19 weeks. A first release would be in front of real customers after about 10 weeks. Running it costs £103 a month: £95 for hosting and about £8 for the app stores.
Build it, rent it, or keep the spreadsheet
The same three-year view for the trades example above, against the two things most businesses do instead.
| Build your own | Off-the-shelf software | Spreadsheets | |
|---|---|---|---|
| Up front | £39,500, fixed per phase | Setup, if the vendor charges for it | Nothing |
| Each month | £95 hosting, support from £450 | A fee for every user, every month | Staff time |
| Over three years | £59,120 with the £450 support tier | Users × monthly fee × 36, and it keeps going | About £127,000 of staff time at 46 hours a week |
| Fits how you work | Yes, it is built around it | You work around the product | Until the person who built it leaves |
| Who owns it | You, code included | The vendor | You, in pieces |
What most quotes leave out
VAT comes first. UK agency quotes are normally exclusive of it, so a £39,500 build is £47,400 if your business cannot reclaim it. Hosting is permanent, and support is a monthly arrangement that is seldom in the build price. Moving your existing data is the part people forget most often: years of spreadsheets with inconsistent customer names take real effort to clean before anyone can use the new system. This calculator prices data migration in when you tell it you are replacing something.
For the reasoning behind the bands and how UK day rates compare, read what custom software costs in the UK.
Common questions
How much does an app cost to build in the UK?
A web app for your own team covering one job starts at about £16,000. A system with several connected areas of work usually runs £30,000 to £75,000, and a customer-facing product with a mobile app £50,000 to £120,000. Every figure is days multiplied by our rate of £800 a day, and we quote it as a fixed price for each phase.
How accurate is the calculator?
It uses the same day bands we quote from, so it is a fair guide to the size of the job. It is not a quote. Undocumented systems, awkward integrations and data that needs cleaning all add days, so the price after a proper scoping conversation can come out higher.
Why does a mobile app cost more than a web app?
A mobile app needs a server behind it to hold the data and talk to your other systems, and it has to be tested and released on iPhone and Android. Mobile alone adds about 15 per cent over the web version, and a web app plus a mobile app adds about 30 per cent.
What does an app cost to run once it is built?
Our hosting is £95 a month for each app in production, or £195 for a business-critical one with tested restores, out-of-hours alerts and a staging copy. Mobile apps add the Apple Developer Program at 99 US dollars a year. Support starts at £450 a month for five hours, with monitoring and security patches included.
Do you quote a fixed price?
Yes. Once the work is scoped we give a fixed price for each phase, starting with a first release you can use on its own. The days behind each phase are there for anyone who wants to check them.
What is included in the estimate?
Logins and permissions, an admin back office so your team can manage the system themselves, interface design and testing with your people, every integration you pick, moving your existing data across, and data protection work where you hold personal data. None of those are extras.
Can I keep the estimate?
Yes. Enter your email address on the result and the estimate downloads as a PDF with every answer and figure in it. We keep a copy, and we will only be in touch if you ask.