
calculator.net
CalcFormula
boilerfeedpumpcalculation.site
Free data center and critical facility calculators: UPS runtime, cooling load, CFM, rack power, generator sizing, kVA, PUE and dew point. Every formula shown.

Mailflow.sh
Stackmail is a webmail service whereby you can log in to your emails from any browser at any time!

Which is more popular?
Website, pricing, platforms and company facts side by side.
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| Website | loadcairn.com | stackmail.com |
| Pricing | — | |
| Company | 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.


LoadCairn is a set of free planning and sizing calculators for data centers and critical facilities. Every calculator shows its formula and assumptions, so engineers can check the math instead of trusting a black box. Calculators include: - UPS runtime - Cooling load - Airflow / CFM - Rack power...
No description of StackMail yet.
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


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Overall verdict
Why this product is good
Recommended for
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing LoadCairn and StackMail.
LoadCairn's answer
Every calculator shows its formula, inputs and assumptions, with references to ASHRAE and NIST. Engineers can check the math instead of trusting a vendor tool that hides it.
LoadCairn's answer
Vendor calculators from APC, Eaton and Vertiv are tied to their own products and don't show their work. LoadCairn is vendor-neutral, free with no account, and covers power, cooling and facility metrics in one place. It also works offline in data halls with no signal.
LoadCairn's answer
Critical facility engineers, data center technicians, facility managers, MEP consultants, data center project teams and students.
LoadCairn's answer
I've worked in data centers for 20 years. Most sizing still happens in old spreadsheets or vendor tools that won't show the math. I built LoadCairn so engineers have quick, transparent estimates they can defend in a design review.
LoadCairn's answer
A web app built on the Polsia platform. It installs on phone or laptop as a progressive web app (PWA) and works offline.
LoadCairn's answer
Not available at this thime.
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