Worldwide Software & Public Cloud Services Spending Guide 2025

Pub. 7/18/2026 2
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I've been working with IT spending data for over a decade. And every year, when the Worldwide Software and Public Cloud Services Spending Guide drops from IDC, I see the same two reactions: either people treat it like a crystal ball, or they ignore it completely. Both are wrong. In this article, I'll walk you through what the guide actually contains, where it falls short, and — most importantly — how to weaponize it for your own planning.

What Is This Spending Guide, Really?

The official name is IDC's Worldwide Software and Public Cloud Services Spending Guide. It's a market forecast that breaks down spending across dozens of software categories (like SaaS, PaaS, IaaS) and 50+ countries. The data comes from surveys, vendor reports, and macroeconomic modeling. I've attended their webinars and even argued with their analysts over methodology.

Here's the thing most people miss: the guide is not a prediction of what will happen — it's a projection based on current trends. And it's updated multiple times a year. So the version you read in March might be wildly different from the one in October. I once saw a projection for a specific region get revised by 20% in six months. That's not a flaw; it's a feature if you use it right.

Quick takeaway: The guide covers software (on-premise + cloud) and public cloud services. It segments by deployment type, industry, and company size. If you're in IT procurement or finance, this is your roadmap — but you need to know the potholes.

I pulled the latest data from the guide (the most recent version I have access to). Here are the three trends that should keep you up at night:

SaaS Continues to Dominate, but PaaS Is Catching Up

SaaS still takes the biggest slice — about 45% of public cloud spending. But platform services (PaaS) are growing faster, especially around AI/ML workloads. If your organization is heavy on custom development, PaaS costs will eat your budget faster than you expect. I've seen teams get surprised by the “serverless tax” where per-invocation costs add up silently.

Hyperscalers Are Not the Only Game in Town

AWS, Azure, and Google Cloud get all the press. But regional providers (like Alibaba Cloud in Asia, OVHcloud in Europe) are growing faster in some segments. The guide breaks this down by geography. I once helped a client shift 30% of their workload to a local provider in Germany — saved them 18% with better latency.

AI Is the Wild Card That Skews Every Forecast

Every vendor is adding AI features, and the spending on AI infrastructure (GPUs, specialized PaaS) is exploding. The guide now includes a separate AI software category. But here's my gripe: the forecast for AI assumes a linear growth that I think is too conservative. In my own tracking, GPU rental costs have tripled in some regions. Don't trust the numbers blindly — add a buffer of 50% for any AI-related line item.

How to Use the Guide for Budgeting

Alright, enough background. Let's get practical. Here's my step-by-step process:

  1. Download the raw tables. Don't just read the executive summary. Get the spreadsheet with country-, industry-, and segment-level data. IDC offers these through their website or third-party resellers.
  2. Filter for your region and industry. For example, if you're in healthcare in the UK, isolate that row. The global average growth rate is useless — what matters is your specific segment.
  3. Compare with your internal data. Pull your last 12 months of spend by software category. If your growth rate is 20% but the guide says 12% for your segment, you need to understand why. Are you over-investing? Or under-forecasting?
  4. Build three scenarios: optimistic (use the guide's lower bound), realistic (mid-point), and conservative (upper bound plus 10% buffer). I always add a buffer because the guide tends to be a bit rosy.
  5. Monitor the revision history. The guide gets updated quarterly. Set a calendar reminder to check for new releases. If a revision dramatically changes your segment, adjust your budget mid-year.
One more tip: The guide includes “as-a-service” spending only. If you still run on-premise software, you need to combine it with other sources like Gartner's IT spending forecast. I've seen CFOs get misled because they looked only at cloud numbers.

Common Mistakes I See All the Time

I've reviewed dozens of budget plans that referenced this guide. Here are the three biggest blunders:

  • Ignoring currency effects. The guide is in US dollars. If your budget is in euros or yen, exchange rates can swing the numbers by 5-10%. Always convert at current rates, not the guide's assumed rate.
  • Copying the growth rate blindly. The guide gives an average growth rate for a segment. But your company might be scaling up or down. If you're a startup growing 200% year-over-year, the guide's 15% is irrelevant — use it only as a sanity check for market context.
  • Forgetting about migration costs. The guide tracks spending on cloud services, not the cost of moving to cloud. I've seen companies budget $1M for SaaS but overlook the $500K migration consulting. That's a recipe for surprise and overspend.

Case Study: How a Mid-Size Company Saved 30%

Let me tell you about a client — let's call them FinServCo (a financial services firm with 2,000 employees). They were spending about $5M annually on public cloud and software. Their cloud costs were growing 25% year-over-year, and leadership wanted to cut it to 10%.

I pulled the IDC spending guide for the “financial services” vertical in North America. The guide showed that the average growth rate for public cloud in that segment was 18%. So FinServCo was actually above average — a red flag. We dug deeper: they were using five different cloud providers and had no reserved instances.

Here's what we did:

  • Consolidated workloads to two providers based on guide's region-specific pricing trends.
  • Used the guide's forecast for IaaS growth to negotiate a 3-year commit with AWS (they wanted the guaranteed spend).
  • Shifted non-critical dev/test workloads to a local provider that the guide showed was growing fast — and they offered lower rates.

Result: within 12 months, their cloud spend grew only 8% (down from 25%), and absolute savings of $1.2M. The guide wasn't the only tool, but it gave us the industry benchmark to make the case.

Frequently Asked Questions

The spending guide says SaaS will grow 18% next year. Should I increase my SaaS budget by exactly 18%?
No way. That 18% is a market average across all industries and company sizes. Your specific situation might be totally different. I've seen companies double their SaaS spend because of a digital transformation initiative — in that case, 18% is useless. Use the guide to check if your planned growth is within a reasonable range, but never as a straight multiplication factor.
How often should I check the spending guide for updates during budget planning?
At least twice: once when you start drafting (use the latest version), and once before final approval (in case a revision dropped). I also recommend subscribing to IDC's email alerts for the specific segments you track. I missed a revision once that changed the forecast for my client's region by 12% — never again.
Can I use this guide for small businesses with less than 50 employees?
Yes, but with caution. The guide does break out spending by company size (small, medium, large). However, the sample size for small businesses is smaller, so the numbers can be volatile. I'd cross-reference with a survey from a small business association. For my own consulting with startups, I treat the guide as a directional signal, not a precise target.
What's the biggest gap between the guide and real-world spending?
In my experience, the guide underestimates shadow IT spending. Many departments buy SaaS directly without IT's knowledge. The guide relies on vendor-reported revenue, which misses those unmanaged purchases. I always advise clients to add 15-20% to the guide's SaaS numbers to account for shadow IT. It's a dirty secret that vendors don't want to discuss.

This article was fact-checked against the latest publicly available IDC spending guide excerpts and cross-referenced with personal consulting notes. All data points reflect the author's interpretation and should be verified before making financial decisions.

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