A long time ago Google used to have a program called "bureaucracy busters," where submissions were reviewed by the CFO to find internal barriers to getting things done.
On the topic of calculators. I discovered Figr[1] on HN a while ago, and it really helps when doing one off multi variable thing, like helping a customer estimate their bill etc.
Kudos on building this. I occasionally search for these on Google and am always disappointed by the mess. Bookmarked.