Free IT Infrastructure Calculators and Tools
RACKCRUNCH provides free calculators, technical checks and product support dates for people who build and run IT infrastructure. No account is needed.
27 free calculators and checks for storage, networking, power, licensing and Linux administration, plus end of life dates for 483 products. No sign-up. Every result shows its formula or rule.
End of life lookup
Is it still supported? End of life, end of support and security fix dates for 483 products: Windows, Windows Server, macOS, Ubuntu, SQL Server, PHP, Python and more. Plus 13 vendor-direct hardware and firmware collections in the same directory.
Popular: Microsoft Windows Server | Microsoft SQL Server | VMware ESXi | Red Hat Enterprise Linux | Ubuntu | Microsoft Windows | Debian | Microsoft Exchange | Microsoft Office | Apple macOS | All 483 products
Storage
- RAID Calculator
Usable capacity, speed and drive-failure tolerance for RAID 0 to 60. - RAID Rebuild
Rebuild time and unrecoverable read error risk while an array is degraded. - IOPS / Throughput
Convert between IOPS, block size and MB/s. - Transfer Time
How long a migration or backup copy takes at a given link speed. - Backup Capacity
Backup storage needed for your retention and change rate. - CCTV Storage
Video storage for cameras, bitrate and days kept. - ZFS RAIDZ Capacity
Usable ZFS space for RAIDZ1, RAIDZ2, RAIDZ3 and mirrors, following OpenZFS math.
Network
- Subnet Calculator
IPv4 network, mask, broadcast and usable host range from a CIDR. - VLSM Planner
Split an IPv4 block into right-sized subnets. - IPv6 Subnet
IPv6 prefix ranges and how many subnets fit. - PoE Budget
Whether a switch PoE budget covers your devices. - VoIP Erlang B
SIP trunks or lines needed for a call load (Erlang B). - SSL Expiry
When a site certificate expires, read live. - Security Headers
Which HTTP security headers a site sends, with the reason for each. - DNS Lookup
A, MX, TXT, NS and other DNS records with TTLs. - SPF / DMARC Checker
Power
- Rack Power
Rack power draw, facility load with PUE, heat (BTU/hr) and monthly cost. - UPS Runtime
UPS battery runtime at your load. - Power Cost
What equipment costs to run per month and year.
Planning
- VM Host Sizing
Hosts needed for your VMs, with failover headroom. - Windows Licensing
Windows Server core licenses for a host or cluster. - Azure Hybrid Benefit Cores
Azure VM sizes to Windows Server core requirements and 8-core pack counts. - SQL Server Licensing
SQL Server 2025 and 2022 core licenses, packs and CALs, with the rule for each line. - Downtime Cost
What an outage costs per hour and per incident. - End of Life Lookup
End of life and support dates for every version of a product.
Linux
- chmod Calculator
Convert Linux permissions between numbers (755) and letters (rwxr-xr-x). - Cron Expression
Read a cron expression in plain English and see its next run times. - systemd Unit Generator
Build a systemd .service file with safe quoting and common hardening options.
How RACKCRUNCH works
- Every calculator lists its formula and assumptions on the Methodology page. Licensing and end of life pages cite their sources.
- Calculations run in your browser. The SSL, security header, DNS and SPF/DMARC tools send the domain you enter to our server to read public certificate, header or DNS data.
- Bad input shows an error, not a made-up number. Found a wrong result? Tell us.