What does it cost to host a SaaS app? An estimate method

By Rohit Athaide · Published 4 Nov 2026

Short answer: there is no single number for hosting a SaaS product, but there is a method that gets you a defensible range in an afternoon. Describe the load, list the building blocks, price them, add what the estimator leaves out, and stress test the result.

Key points

• Start from four load figures: users, requests per user, data stored, data sent.
• List servers, database, load balancer, storage, data out and extras.
• Price with an estimator in one region group on all clouds.
• Add staff tools, third-party services, test environments and support.
• Stress test with double the users.

Step 1: how do I describe the load?

Write down four figures, even as guesses:

1. Active users per month and peak users at once.
2. Requests per user per day.
3. Data stored per user.
4. Data sent to each user per month.

Step 2: which building blocks do I list?

Step 3: how do I price it?

Put the figures in the web app estimator. It prices each block on four clouds in the same region group and shows the lines that make up the total. Start with the presets and change the figures to yours.

What does a worked example look like?

Made-up round numbers to show the method, not real prices. A product with 2,000 monthly active users, 50 requests per user per day, 200 MB stored per user, and 1 GB sent per user per month.

Twelve requests per second is a small load: two modest servers cover it for availability. The line to watch is data out: 2,000 GB at a made-up 0.09 per GB is 180 a month, probably more than the two servers at 2 x 40 = 80. Many small SaaS bills are dominated by data out and the database, not by servers. If most of the 1 GB per user is images or downloads, a CDN could cut it. Price the blocks you identified in step 2 with the estimator.

Step 4: what does the estimator leave out?

• Staff time and tools such as error tracking and CI.
• Third-party services, such as email and payments.
• Test and staging environments. See dev and test costs.
• Support. See support plans.

Step 5: how do I stress test?

Double the users and see which lines rise. Fixed lines, such as a database, change in steps. Traffic lines grow in a line. The one that grows fastest is where to look for savings first.

Which traps inflate the bill?

• Sizing for a peak you never reach.
• One load balancer per service.
• A multi-zone design from day one for a product with ten users. See multi-AZ costs.
• Verbose logging.
• Leaving test environments running.

Decision checklist

• Are the four load figures written down?
• Is each building block priced in the same region group?
• Are staff tools, third-party services and support added?
• Did I double the users and look at what grew?

Next steps

For a worked comparison, read what a web app costs per month. Plan the money side with planning a cloud budget and keep an eye on cost per customer as you grow.