It varies based on the program, but at a bare minimum, almost every school is going to require Calculus and Linear Algebra. And at good programs (Top 50), you probably won't be able to get in with that little math unless you have already published in economics journals as an undergrad, or are exceptional in some other way.
Ideally, undergrad mathematics coursework of a successful PhD applicant will include:
Calc
Multivariable Calc
Linear Algebra
Differential Equations
Real Analysis
Probability Theory
Game Theory
Statistics (the mathy kind, not the nonsense they teach education majors)
Each econ department should have some indication of the level of math education they prefer from applicants on their website. Check there for specific info.
In short: take as much math as you possibly can.