budgetMsForRefreshRate function

double budgetMsForRefreshRate(
  1. double hz
)

The per-frame budget for a display refresh rate: 16.7ms at 60Hz, 11.1ms at 90Hz, 8.3ms at 120Hz. Judging a 120Hz phone against 16ms grades a visibly janky app as "A".

Implementation

double budgetMsForRefreshRate(double hz) => 1000.0 / hz;