[stextbox id=alert]Hi Everyone! I have taken the XLS file offline. There were a ton of bugs, as pointed out in comments and through emails/Twitter. I am working on solidifying the functions and migrating this to an actual application instead of Excel. In the meantime, you can check out other calculators here.[/stextbox]

**Updated: **I am going to take this offline for awhile. I really need to sit back down and go over what I had intended this to be used for since I’m starting to mix all types of things on this sheet and my terminology I’m sure does not match correctly with what I’m trying to express in the sheet. I’ll repost the download when I have had time to review.

**Updated**: You can download the Excel workbook RAID-and-IOPS which has updates/bugfixes through December 3, 2012 as noted in comments below.

I’m working on an Excel spreadsheet (cheatsheet) that will allow for user input to calculate some of the following:

- Calculate IOPS, Usable Space, MB/s based on Number of Disks, Spindle Speed, RAID type and Read/Write Percentages.
- Calculate Number of Disks required for IOPs
- Calculate/Convert MB/s to IOPS
- Calculate/Convert IOPS to MB/s

It also contains some basic information and formulas:

- Formula for Total Raw IOPS
- Formula for Functional IOPS
- Formula for MB/s from IOPS
- Formula for IOPS from MB/s
- Formula to determine number disks required for IOPs based on RAID type and spindle speed.

Here’s a screenshot:

RAID/IOPS Calculator Cheat Sheet

Here are some of the formulas used:

- Total Raw IOPS = Disk Speed IOPS * Number of Disks
- Functional IOPS = (((Total Raw IOPS*Write%))/(RAID Penalty))+(Total Raw IOPS*Read%)
- MB/s = (IOPS * KB per IO) / 1024
- IOPS=(MBps Throughput / KB per IO) * 1024
- Formula to determine disks required for IOPs (total required IOPS * read%) + (total required IOPS * write% * RAID penalty) = total IOPS required take that and divide by IOPS provided by disk type (15k=175, 10k=125, etc.)