It's not "just" a calculator.
I use it for all of my invoicing.
I also use another Quickbooks program called customer manager for all my bookings.
You can put in as much or as little info that you want.
It even does mail outs for you, reminders, etc;
& they (forgotten the word)

mix in with Word/Excel/ etc; as well.
Log onto their site and go for a demo run, or down at (probably) Walmart or that big blue office supply shop, you can get a "How to use Quicken/Quickbooks" cd for about $5