How to Calculate ROI on Custom Software Development
Custom software is an investment. Here's how to quantify the return: time saved, errors avoided, revenue enabled, and avoided SaaS fees. A practical framework for justifying the investment to stakeholders.
Table of Contents
ROI Formula
ROI = (Benefits - Cost) / Cost × 100. Benefits are the annual value you get from the software. Cost is the one-time development cost plus annual maintenance (typically 15-20% of build cost). For example: $50K build + $10K/year maintenance. Year 1 cost = $60K.
What Counts as Benefits
- Hours saved × hourly rate — If the software saves 20 hrs/week and your blended rate is $50/hr, that's $52K/year.
- Error reduction cost — Fewer mistakes, fewer rework hours, fewer compliance issues. Estimate based on past error rates and cost per error.
- Revenue from new capabilities — Can you serve more customers? Launch a new product? Close deals faster? Quantify the revenue impact.
- Avoided SaaS fees — If you're replacing 3 tools at $200/user/month for 20 users, that's $144K/year. Custom has no per-seat fees.
Worked Example
$50K custom tool saves 20 hrs/week × $50/hr × 52 weeks = $52K/year in labor. Year 1 cost: $50K + $10K maintenance = $60K. ROI in year 1: ($52K - $60K) / $60K = -13% (payback in ~14 months).
By year 2: $52K benefit, $10K maintenance. Cumulative ROI: ($104K - $70K) / $70K = 49%. Plus: fewer errors, faster decisions, scalability. The intangibles often push ROI higher over 3-5 years.
Intangible Benefits
Some benefits are hard to quantify: better decisions from real-time data, competitive advantage, employee satisfaction (less manual work), compliance and audit readiness. Include a qualitative section in your ROI case. Stakeholders care about risk reduction and strategic value, not just labor savings.
Frequently Asked Questions
What payback period is reasonable?
12-24 months is typical. If payback is 3+ years, consider whether the scope is too large or the benefits are overstated. Start smaller if needed.
How do we get stakeholder buy-in?
Present the ROI case with conservative estimates. Include the cost of inaction: what happens if we don't automate? Lost efficiency, errors, scaling limits.