Software Maintenance Cost Calculator
Custom software isn't done when it ships, it needs bug fixes, updates, hosting and support every year. Enter your build cost to estimate your annual maintenance budget and total cost of ownership over 3, 5 or 7 years.
How it works
Software maintenance is everything that keeps a live product healthy after launch: fixing bugs, shipping small feature updates, patching dependencies and security holes, paying for hosting, and monitoring uptime. The most widely used rule of thumb is to budget an annual amount equal to a fixed percentage of what the software originally cost to build.
Most teams land between 15% and 20% of the build cost per year for a reasonably clean, well-documented system. Simpler apps sit at the low end, while legacy codebases, high technical debt, or regulated and high-availability systems push the figure toward 22% or higher. This calculator multiplies your build cost by the rate you choose, projects it across your chosen horizon, and splits the annual figure into four practical buckets so you can see where the money actually goes.
annual maintenance = build cost × annual rate · total = annual × years · split: bug fixes 30%, features 25%, support 25%, hosting 20%
If you don't yet know your build cost, estimate it first with our software development cost calculator, or weigh a custom build against off-the-shelf tools using the build-vs-buy calculator.
FAQs
What is a normal annual software maintenance cost?
The commonly cited industry range is 15-20% of the original build cost per year. A $150,000 build typically carries roughly $22,500-$30,000 in annual maintenance. Simple apps trend lower; complex, legacy, or regulated systems trend higher.
What does the maintenance budget actually cover?
Four main areas: fixing bugs and errors, shipping small feature updates and improvements, hosting and cloud infrastructure, and ongoing support and monitoring (including security patches and dependency upgrades). This tool splits your annual figure across those buckets.
Why is my rate above 20%?
Rates above 20% usually reflect legacy code, accumulated technical debt, strict compliance requirements, or high-availability demands. It's a valid budget, but a code-health review often reduces it back toward the 15-20% range over time.