How familiar are you with algebra? The stronger you are with algebra, the easier you will find Calculus. You will also need a relatively strong understanding of trigonometry, but I've mostly been able to review the trig I need as it comes up. That being said, don't feel like you need to be an expert at all prior math before jumping into Calc. In fact, Calculus might be the class you finally grok algebra since you'll use it so much!

Here is a good review of the algebra you'll use in a Calc I course: http://tutorial.math.lamar.edu/Extras/AlgebraTrigReview/Alge...

I had a humbling experience last year when I browsed the available courses until I found one that only contained math I'm already familiar with and I had to go all the way back to fourth year elementary school. :/

I went back to school for CS, and ended up taking courses starting at Grade 10 math as prereqs so that I could rebuild my math knowledge. Even the start of that was rough, since I hadn't done math in a long, long time. By the end of the course, I was much stronger.

What I'm trying to say is that you've made a good decision by jumping way back. Once thing I realized pretty quickly is that to do well in math, you need to know the prior content pretty well. And for the next thing, the current content pretty. And so on. If you can stay on top of it, it 's a lot less challenging (and more interesting).

How were you able to determine what level you were at?

I started at precalculus and worked my way back until I found a video that didn't assume I already knew something I don't already know.

Could be that you know a lot of maths at a higher level than that, but your education just has a lot of holes in it.

If only that were true. :) I only know cross multiplication and basic arithmetic, excepting long division.

We all start somewhere! One of the beauties of math is it’s hierarchical structure. Once you figure out where you’re at, it’s just a matter of progressing further up the hierarchy of abstraction (spoken by someone who has only made it to Calculus in the hierarchy)

I really want to make a site that expresses this like a skill tree you'd find in an RPG or in Civilisation.

Duolingo has something like this. I rather like it.

That was my experience. I took through calculus in high school, but that was a lot of years ago. I discovered my trig and logs were very weak, and started back at algebra 2 and worked my way forward. A lot of it was review, but a lot of it felt completely new to me.

I'm in the middle of a very similar experience.

I run into this every time I help my kids with their math homework- even for subjects I thought I had learned comprehensively their curriculum covers branches/approaches I've never seen before, down to elementary school work.