How this calculator works
| Metric | Formula |
|---|---|
| Buy, per year | users × (1 + growth)^(year−1) × seat price × (1 + increase)^(year−1) × 12 + add-ons × 12 |
| Build, per year | build cost × maintenance % + hosting × 12 |
| Break-even year | first year where cumulative buy cost ≥ cumulative build cost |
Worked example
With these inputs:
- Currency: USD ($)
- Users today: 50
- User growth per year: 20%
- SaaS price per user per month: 45
- SaaS price increase per year: 7%
- SaaS add-ons & integrations per month: 300
- SaaS one-off setup & migration: 8,000
- Custom build cost (from your quote): 90,000
- Custom maintenance per year: 20 % of build
- Custom hosting per month: 400
- Years to compare: 5
Cheaper over 5 years: Build — saves $58,725. Over 5 years, buying SaaS costs about $262,725 and building custom software about $204,000. Building breaks even in year 4.
| Total cost to buy (SaaS) | $262,725 |
|---|---|
| Total cost to build (custom) | $204,000 |
| Break-even year | Year 4 |
| Users in final year | 104 |
| Cost per user per month — buy / build | $56.99 / $44.25 |
Open this example in the calculator
When to buy and when to build
| Buy SaaS when… | Build custom when… |
|---|---|
| The process is standard (email, accounting, HR basics) | The process is how you compete |
| You need it running next week | You can invest a few months for a better fit |
| User numbers are small and stable | Per-user fees grow quickly with your team or customers |
| You have no one to own the software | You can own it, in-house or with a partner |
| Several SaaS tools already do the job well together | You are paying for several tools and gluing them together |
Costs that are easy to miss
- SaaS: price rises at renewal, premium tiers for features you need, integration tools and consultants.
- SaaS: staff time working around features that do not fit.
- Custom: maintenance, security updates and hosting every year.
- Custom: product ownership — someone has to decide what to build next.
The hybrid option
Many businesses buy SaaS for standard functions and build a thin custom layer — a portal, workflow or integration — that connects them and handles what makes the business different. This often gives the best of both.
Open this calculator with your numbers
Every option can be set in the web address, so you can bookmark a scenario or send it to a colleague. AI assistants such as ChatGPT, Gemini, Claude and Perplexity can use the same parameters to open this calculator with your numbers and the result already on the page.
| Parameter | What it sets | Accepted values |
|---|---|---|
currency |
Currency | one of USD, INR, AED, GBP, EUR |
users |
Users today | number from 1 to 1000000, default 50 |
user_growth |
User growth per year | number from -50 to 300 (%), default 20 |
seat_price |
SaaS price per user per month | number from 0 to 100000 (in the chosen currency), default 45 |
price_increase |
SaaS price increase per year | number from 0 to 100 (%), default 7 |
saas_extras |
SaaS add-ons & integrations per month | number from 0 to 10000000 (in the chosen currency), default 300 |
saas_setup |
SaaS one-off setup & migration | number from 0 to 100000000 (in the chosen currency), default 8000 |
build_cost |
Custom build cost (from your quote) | number from 0 to 1000000000 (in the chosen currency), default 90000 |
maintenance |
Custom maintenance per year | number from 0 to 100 (% of build), default 20 |
hosting |
Custom hosting per month | number from 0 to 10000000 (in the chosen currency), default 400 |
years |
Years to compare | number from 1 to 10, default 5 |
Also available as plain text for AI assistants and a free JSON API (OpenAPI spec).
Last reviewed by the Infikey Technologies team.
Disclaimer
This calculator is provided free for general information and planning only. Results are estimates based on the inputs you enter and the assumptions described on this page, reference data such as published prices may change, and actual costs and outcomes will differ. Nothing on this page is financial, legal, tax, investment or other professional advice. Infikey Technologies Private Limited, Infikey Technologies LLC and their directors, employees and affiliates make no warranty, express or implied, about the accuracy, completeness or suitability of this tool or its results, and accept no liability for any loss or damage, direct or indirect, arising from its use or from reliance on its results. Verify all figures independently and seek professional advice before making any decision. Use of this tool is at your own risk.