Generic charts tell you what an average golfer carries. This tool fits the whole bag to your data — start from swing speed, or calibrate from carries you already trust.
Assumes efficient contact (smash ~1.48) and neutral launch. Don't know your speed? Use the calibrate mode with your driver carry — it estimates swing speed for you.
Launch monitor or GPS averages work best. One club calibrates the bag; two to four sharpens the fit.