Understanding the math of relativity?

[Skynt]

What sort of math background in terms of subject matter would one have to understand in order to learn about relativity and Einstein's works?

I'm sure vector calculus would be one, linear algebra...?

[mgb_phys]

For special relativity not too bad - you just need pythagorus' theorem to derive Lorentz contraction etc.
For general relativity - tensors (I hit my personal maths brick wall after this!)