Effective hourly rate is your monthly pay divided by the hours you actually work, including unpaid overtime. An offer paying 20% more for 50-hour weeks can be worth less per hour than a smaller offer with a 40-hour week.
Commute cost counts both money and time. The money comes off your pay. The time is shown separately, because two hours a day is 40 hours a month of your life that no salary line mentions.
Benefits are added only if you enter a monthly figure you can actually put a number on — health cover you would otherwise buy, a fuel or internet allowance, a bonus you are confident about. Do not count a bonus that is discretionary, and do not count equity in a company whose shares you cannot sell.
This tool does no tax calculation. Enter take-home figures if you know them, or gross figures for all offers so the comparison stays fair.