Software development cost: how to estimate it and compare quotes
Software development cost is the sum of analysis, design, build and test effort, plus infrastructure and maintenance. This guide explains what drives the figure and how to calculate it. It also shows how to compare quotes from different vendors.
Why is there no single software development cost?
Software is not a product you pick off a shelf; it is work done to order. For this reason, a screen count alone does not set the price. Two projects can look identical from the outside. However, one may have a single approval step while the other has a five-level chain.
In short, software development cost depends on how much effort the work needs. So “How much does an app cost?” has no single answer. The better question is “How many person-months does my scope take?”
How do you calculate software development cost?
The most common method is the person-month. One person-month is the work one specialist completes in a month. First, the team splits the work into parts and estimates each one. Then it multiplies the total by the monthly cost of the team.
| Item | When it occurs | What it depends on |
|---|---|---|
| Analysis and design | Before the build | Process complexity, number of screens |
| Build and test | During the first release | Modules, business rules, integrations |
| Data migration | Before launch | Volume and quality of existing data |
| Infrastructure and licences | Monthly or yearly | User numbers, storage, third-party services |
| Maintenance and growth | After launch | Response time expectations, new features |
7 factors behind software development cost
- Scope: The number of modules and their business rules directly raise total effort.
- User roles: Each new role adds permission rules and more test scenarios.
- Integrations: Connecting to ERP, accounting or payment services takes extra effort.
- Platforms: Asking for web, iOS and Android together increases the amount of work.
- Data migration: Messy spreadsheets need cleaning, which extends the schedule.
- Security and compliance: Audit logs, privacy processes and backups belong in the plan from day one.
- Schedule pressure: A bigger team does not always shorten the timeline in proportion.
Scope usually has the strongest effect on software development cost, because each new feature adds design, build, test and maintenance work together. For projects with a mobile side, our mobile app guide adds further detail.
Why do early estimates miss the mark?
A figure given before analysis is more of an assumption than an estimate. The “cone of uncertainty” in software estimation describes this. According to a paper published by Construx, estimates at the initial concept stage can be off by a factor of 4 in either direction. Moreover, that range represents the best case.
Large projects show a similar picture. A 2012 study by McKinsey and the University of Oxford looked at more than 5,400 IT projects. Those with budgets above $15 million ran 45% over budget on average. They also delivered 56% less value than predicted.
These figures do not map directly onto small projects. Still, the lesson holds: settle the scope first, then discuss numbers. Therefore, an initial analysis is the cheapest way to reduce budget risk.
Fixed price or time and materials?
| Criterion | Fixed price | Time and materials |
|---|---|---|
| Best suited to | Small jobs with clear scope | Evolving, long-running products |
| Budget visibility | Known from the start | Tracked period by period |
| Changes | Need an additional quote | Move into the next period |
| Main risk | Price includes a risk margin | Scope can grow unchecked |
In practice, the two models also work together. For example, analysis and the first release can run on a fixed price, while later work uses monthly capacity. Whichever you choose, write down how change requests are priced.
5 ways to reduce software development cost
- Start small: Build the highest-value features first; our MVP guide explains how to choose.
- Reuse existing parts: Connect ready-made services for payments, email and maps.
- Name one decision maker: Delayed approvals burn team time and therefore budget.
- Clean your data early: Tidy data noticeably cuts migration effort.
- Agree on maintenance up front: This prevents surprise costs after launch.
On the other hand, the cheapest quote does not always save money. Weak testing or poor architecture simply moves software development cost to the period after launch. To see the full journey, read our custom software development process guide.
How do you compare vendor quotes?
The gap between two quotes is often a difference in scope rather than price. So bring the quotes onto common ground first. Then look for answers to these questions in each one:
- Which modules and features are in scope, and which are out?
- Does the quote state the person-months or team size behind it?
- Do testing, data migration and launch sit inside the total?
- Who owns the source code and the data?
- What are the maintenance fee and the response time after launch?
- How does the vendor price change requests?
How Coratlas prepares a software development cost proposal
At Coratlas, we listen to your needs and define the scope with you before we name a price. The initial consultation is free, and we reply within 1 business day. After that, we present a written proposal split into phases, outputs and responsibilities.
See our custom software development page for the service scope. If you are weighing up an off-the-shelf package, our custom software guide compares the two paths.
Frequently asked questions
Why does software development cost vary so much between vendors?
Vendors interpret scope differently and work with different team structures. In addition, some quotes leave out testing, data migration or maintenance. So compare quotes on the same scope.
Can I get a price without an analysis?
You can get a rough range, but that figure is not firm. Early estimates can drift a long way from the final number. For a binding figure, put the scope in writing first.
How much does yearly maintenance cost?
Maintenance is a lasting part of software development cost, and there is no single percentage. The amount depends on response times, new feature expectations and infrastructure. Therefore, ask for maintenance terms along with the first quote.
Is off-the-shelf software always cheaper?
Usually yes at the start. However, per-user licences and customisation fees add up over time. Compare the total over several years before you decide.
This article is for general information only and is not legal, financial or medical advice. Consult a qualified professional about your own situation.