Spreadsheets by hand
 

No need to hunt a program that's confusing and worthless, I've been doing these for 25 years, thanks to John Lawlor's Auto Math Handbook. Takes maybe 10 minutes. Here's an example of the way I use most. Get a green highlighter if you want it easier to see your powerband.
http://i1316.photobucket.com/albums/...ps1f74e8f1.jpg
This one's for a mild-cammed LSx V8 with long-tubes (headers) in a front-engine, rear-drive sports car. This version of the T56 was used in all '98-'02 Z28s, with ratios of 2.66 / 1.78 / 1.30 / 1.00 / 0.74 / 0.50, and the assumed axle was a 3.5454545:1-geared Ford 8.8"
If the drag is low enough, even a 4.8L can pull this cruise RPM without lugging, even the undetectable-to-the-driver I call "Microlugging", which is the most harmful to MPG.

Is that a MPH vs. RPM chart? Those are reasonably easy, if tedious, to do by hand.

When you get to more complex formulae, doing them by hand gets very tedious, lengthy, and error-prone. There's a certain point (in the complexity of the formula) where it's easier to just set up a spreadsheet, and just where that point is depends on who is doing the number crunching. I suspect that for many of us, that point is "anything more complicated than RPM versus speed". ;)

-soD

Part of my point is that noone needs anything beyond what's in that handbook. I know, I've gone way beyond it, invested a lot in going beyond, and ended up wit no practical RoI.
This is just one example I showed, and it's about all any of us really need.
This shows all 6 gears with one axle ratio and one tire size, but it is just as easy to show one trans gear with multiple tire sizes, multiple axle ratios, or both.
Alternately, just set one tire size, then compare 2 axle ratios with 2 6th gear ratios. The T56 offers several choices, for example, and they can be interchanged.
But having these numbers means nothing until you have the hands on experience to feel what the numbers represent. I bought my first Camaro at age 14, and before I turned 15 I had 2.56:1 axle gears for comparison against the 2.41:1s I started with. Once I drove the car both ways, then the spreadsheets gained meaning.
I do find value in finding the cruise RPM of factory combos I can't afford to buy and drive, but sometimes can test-drive by wearing my church clothes and borrowing a nicer car.

https://archive.org/details/VisiCalc_1979_SoftwareArts

Not having the Handbook, I presume you populate each cell by hand? Can you generate bar graphs? Internet Archive has Visicalc (written in 1979 by Dan Bricklin) running in the web browser. It won't initialize in my browser (possibly requires Chrome or turning on Java) and you can't save the result; but you could populate the spreadsheet and take a screenshot and have the same result as doing it on paper.

I'd be interested if you can get it to work in other (non-locked down) browsers.

If the point of this is not having to buy an Office package, you can download something like OpenOffice for free.