What's your SaaS really costing you?
Enter your annual costs to see the true cost of your current system and the payback period on a custom replacement. Results appear instantly; nothing is gated.
What you enter
- Annual licence or subscription cost (£)
- Annual change request and customisation spend (£)
- Workaround labour: hours per week across the team spent on manual processes the software should handle, and an average loaded hourly cost (default £35 per hour)
- Optional: estimated annual cost of downtime or errors (£)
- Rough scope of a replacement build: small (£150k), medium (£250k), large (£350k), or your own figure
How it is calculated
- Workaround labour = hours per week x loaded hourly cost x 46 working weeks
- True annual cost = licence + change requests + workaround labour + downtime and errors
- Custom system run cost = 30% of true annual cost by default (visible and editable), covering hosting, support, and continued development
- Payback period in years = build cost / (true annual cost - run cost)
- A year-by-year chart compares cumulative spend over five years: staying on SaaS versus the build cost plus running costs
How to read your payback period
- Under 2 years: Strong case for replacement
- Payback in under two years is a strong result. Most of our replacement projects land here, usually driven by heavy change request spend or a large workaround burden. The next step is a structured look at scope and data migration.
- 2 to 4 years: Worth a structured evaluation
- Payback between two and four years is the typical range for mid-market operational systems. The case is credible but depends on your assumptions holding, so test the workaround and run cost figures carefully before committing.
- Over 4 years: Replacement may not be the right move yet
- Payback beyond four years suggests your SaaS product is reasonable value today. We would rather tell you that than sell you a build. Revisit the numbers if change request spend grows, workarounds multiply, or renewal pricing jumps.
- No annual saving: No payback at these numbers
- At these figures the custom system would cost as much to run as your current spend, so the build never pays back. That usually means the true annual cost entered is low relative to the run cost assumption. If these numbers reflect reality, keep the SaaS product.
What's your SaaS really costing you?
Enter your annual costs to see the true cost of your current system and the payback period on a custom replacement. Results appear instantly; nothing is gated.
Customisation, paid feature work, and professional services.
Team-wide hours on manual processes the software should handle.
Salary plus overheads. £30 to £45 is typical for UK mid-market.
Lost revenue from outages plus the cost of correcting data errors.
Hosting, support, and continued development, as a percentage of your current true annual cost. Deliberately conservative by default.
Enter at least one annual cost above to see your results.
This calculator totals what your operational SaaS product really costs each year (licence, change requests, workaround labour, and downtime), then shows the payback period on a custom replacement in the £150k to £350k range. Results are instant and ungated, the formulae are published in full, and every assumption is editable. If the payback lands beyond four years, the honest answer is to keep your SaaS product for now.
Why licence fees are the wrong number
The licence line is the sticker price, not the cost. For mid-market operators, the true annual cost of an operational SaaS product routinely runs at several multiples of the licence fee once you count:
- Change request and customisation spend
- Workaround labour: the spreadsheets, re-keying, and reconciliation that bridge the gap between the software and your operating model
- Downtime and the cost of correcting errors
We have written about each of these patterns in detail: where change request money goes, the workaround tax, and a worked example of a £20k licence with a £270k true cost.
How does the calculator work?
The calculator above takes five inputs and shows results instantly, with no email gate. The model is deliberately simple and fully visible:
- Workaround labour is annualised as hours per week, multiplied by a loaded hourly cost, multiplied by 46 working weeks.
- True annual cost is the sum of licence, change requests, workaround labour, and downtime or error costs.
- The custom system’s run cost is deducted before any saving is claimed. The default assumption is 30% of your current true annual cost, covering hosting, support, and continued development. It is deliberately conservative, and you can edit it.
- Payback is the build cost divided by the annual saving.
- The five-year chart compares cumulative spend: staying on SaaS against the build cost plus its running costs.
All figures are in today’s prices, with no inflation or discounting applied. The model also assumes your current SaaS costs would stay flat, which in our experience is generous to the SaaS side of the comparison.
How should you read the result?
The verdict bands are deliberately honest, because a calculator that always says “replace” is a sales tool, not a decision aid:
- Under two years: a strong case. Most of our replacement projects land here, usually driven by heavy change request spend or a large workaround burden.
- Two to four years: worth a structured evaluation. This is the typical range for mid-market operational systems, and the case depends on your assumptions holding.
- Over four years: replacement may not be the right move yet. Your SaaS product is probably reasonable value for your usage today.
If you want to sanity-check an input, the workaround tax post includes a practical method for estimating manual process hours, and the ROI guide for AI-augmented development explains the full cost model behind the build-side figures.
Why are build costs in the £150k to £350k range?
Because AI-augmented delivery has moved them there. Our recent proposals for large greenfield Azure builds are landing at 28 to 34% of what the same work would have cost before AI, at the same quality or better, with full code ownership as standard. The measurement behind that figure is published in our AI Velocity Report.
What should you do with your result?
If the calculator points to a case worth evaluating:
- Read the AI-era SaaS replacement playbook for the full decision framework: when to replace, what to build, and what to leave alone.
- Score your vendor relationship against the SaaS replacement scorecard to test the non-financial factors.
- See what leaving actually involves in the 90-day migration playbook.
Or skip ahead: book a consultation and we will build this cost table for your real numbers, line by line, and tell you honestly whether a replacement stacks up.
Frequently asked questions
How accurate is the SaaS payback calculator?
What counts as workaround labour?
Why does the calculator assume a run cost for the custom system?
What does a replacement build actually cost?
What if the calculator says replacement does not pay back?
Related guides
AI-Augmented Development ROI for UK Mid-Market Buyers
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The AI-Era SaaS Replacement Playbook: When, Why and How to Replace SaaS with Custom Software
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