Free calculator that quantifies the calorie cost of a sedentary desk job. Enter your weight and the hours per day you spend sitting; the tool computes the calories burned versus the alternative of standing or light activity, then projects the difference across a year. It also includes a built-in standing-desk swap so you can see what flipping even part of your day to standing would change. Uses the Compendium of Physical Activities MET values for seated office work — no opinions, just the math.