Build vs Buy Calculator
See whether a recurring SaaS subscription or a one-time custom build is the better investment over time.
The Build vs Buy Calculator compares the total multi-year cost of an existing SaaS subscription against a one-time custom software build, so you can see — in plain numbers — which option actually costs less over time. It's built for founders, product leads, and IT decision-makers who are paying a recurring per-seat fee and wondering whether that spend has crossed the point where owning the software outright would be cheaper.
Enter your monthly per-seat cost, number of seats, and how many years you expect to keep using the tool. If you already have a ballpark custom-build estimate, add it to see a side-by-side comparison and an estimated payback period.
Leave blank to see total SaaS spend and a typical payback range.
How this is calculated
Total SaaS cost = monthly cost per seat × number of seats × 12 × years of use. Payback period (months) = custom build cost ÷ monthly SaaS spend across all seats. This model compares subscription spend against a one-time build cost only — it does not include the ongoing hosting, maintenance, and support cost a custom build requires after launch, so treat the payback figure as a starting point for a fuller total-cost-of-ownership conversation.
Frequently asked questions
How do I decide between building custom software and buying a SaaS subscription?+
Compare the total multi-year cost of the SaaS subscription (monthly seat cost × seats × months) against the one-time cost of a custom build. If the SaaS total exceeds the build cost within your planning horizon, and the workflow is core to your business, a custom build is usually the stronger long-term investment.
What is a typical payback period for a custom build vs SaaS?+
For teams spending a meaningful recurring amount on a SaaS tool, a custom build commonly pays for itself in 12-24 months, after which the SaaS subscription cost that would have continued becomes pure savings.
Does this calculator include ongoing maintenance cost for a custom build?+
No. It compares only the one-time build estimate you enter against the recurring SaaS cost. Custom software still needs ongoing maintenance, hosting, and support — factor that in separately before deciding.
When does buying (SaaS) make more sense than building?+
When the workflow is not core to your competitive advantage, seat counts are small, or requirements change too fast to justify a fixed build — SaaS is usually cheaper and faster to adopt.
What to do with your result
A short payback period is a strong signal that a custom build is worth scoping properly — but the real decision depends on how core the workflow is to your business and how much your requirements are likely to change.
Webvoid Technologies (based in Chittoor, India, working with teams globally) builds custom software that replaces recurring SaaS spend with a system you own. Discuss a custom software build or bring your numbers to a free scoping call.
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