Take your annual goal (3,650,000 steps for a 10,000 daily average), subtract how many steps you've already walked, then divide by the days left in the year. Slacked in January? Your daily target goes above 10,000. Crushed it early? It drops below. The calculator at the top of this page runs that formula every time you update your numbers.

About 5 miles, or 8 kilometres, for most adults. The exact distance depends on your stride length, which is mostly set by your height. A 5'9" (175 cm) person covers roughly 2,000 steps per mile. Taller people need fewer steps to hit the same distance; shorter people need more. NHS: Walking for health

Roughly 300 to 500 calories, depending on your weight, pace, and terrain. A 155-pound (70 kg) person walking at a moderate pace burns around 400 calories per 10,000 steps. Walking faster or uphill burns noticeably more. CDC: Physical activity basics

About 80 to 100 minutes of total walking. At a moderate 100 steps per minute that is 100 minutes; at a brisk 120 steps per minute it is closer to 83 minutes. Most people do not do it all at once. Splitting it across the day (commute, lunch break, evening walk) is much easier to stick to than one long session.

Yes, the science backs it. Hitting 10,000 steps per day is linked to lower risk of cardiovascular disease, type 2 diabetes, and early mortality. You don't need exactly 10,000 to see benefits though. Research suggests 7,000 to 8,000 steps per day captures most of the health gains for the average adult. 10,000 is just a satisfying round number to chase. WHO: Physical activity guidelines

A Japanese marketing campaign from the 1960s. Yamasa Corporation launched a pedometer called the "Manpo-kei" (literally "10,000-step meter") ahead of the 1964 Tokyo Olympics. The number was picked because it was round and motivating, not because any scientist declared it the optimal daily target. Decades of research since then have largely validated it as a solid goal. NCBI: History of the 10,000 steps target