How many calories do I burn doing nothing?

More than you’d guess. A 40-year-old woman, 5 foot 4 and 140 pounds, burns about 1,290 calories a day lying still, and a 40-year-old man, 5 foot 10 and 180 pounds, about 1,730. That’s about 54 to 72 calories an hour for doing nothing at all. This resting burn (BMR) is the biggest part of most people’s day, bigger than all their walking and workouts put together.

Doing nothing feels free. But your heart keeps beating, your brain never switches off, and your liver and kidneys work around the clock. All of that runs on calories.

The simple version

Think of a house in winter with nobody home. The heating and the fridge still run all day. That’s your resting burn. Getting up and moving is the extra on top.

Where it goes

Your organs are small and hungry. Per pound, at rest, the heart and kidneys burn about 200 calories a day, the brain about 110 and the liver about 90. Muscle burns about 6 and fat about 2. Pound for pound, your heart burns more than 30 times what a resting muscle does.

Sitting still against fidgeting

The Compendium of Physical Activities, the standard table of what activities cost, counts sitting quietly as 1.0 MET, your resting rate. Fidgeting your hands while you sit is 1.5, fidgeting your feet 1.8 and standing quietly 1.3. A MET is about 1 calorie per kilogram of body weight per hour. So a 180-pound person who stands instead of sitting for 4 hours burns about 100 more calories.

What to do

• Find your resting number on the BMR calculator.
• Keep your daily target above it. It’s what keeping you alive costs, before you take a step.