How Many Calories Do I Burn Per Hour At Rest? | Simple Math Guide

What “Calories Per Hour At Rest” Actually Means

When you sit or lie quietly, your body still burns energy to keep you alive. Breathing, circulation, body temperature, and cellular work never stop. Scientists call this baseline burn resting metabolic rate (RMR). A close cousin, basal metabolic rate (BMR), is measured under stricter lab conditions. In day-to-day life, RMR is the practical yardstick.

The simple rule: 1 MET equals the energy cost of quiet rest and maps to about 1 kilocalorie per kilogram per hour. That’s why weight drives the math. A 50-kg body typically burns near 50 kcal each hour at rest; a 90-kg body sits closer to 90 kcal. This 1 MET anchor comes from the widely used Compendium of Physical Activities.

Calories Burned Per Hour While Resting: Quick Calculator Steps

Here’s the fast way to get your number without an app:

1. Convert your weight to kilograms: pounds ÷ 2.2046.
2. Multiply by ~1 kcal/kg/h for quiet rest.
3. Round to the nearest 5 if you like clean numbers.

Want a daily estimate? Multiply your hourly figure by 24. That gives a rough “all-day at rest” number. Real life adds meals and movement, so your 24-hour total will land higher.

Typical Numbers By Body Size

The table below uses the 1 MET convention. It gives a broad, in-depth view across common body sizes. Pick the row closest to you for a quick estimate.

Body Weight (kg)	Hourly Calories At Rest	Daily At-Rest (×24)
45	≈ 45 kcal	≈ 1,080 kcal
50	≈ 50 kcal	≈ 1,200 kcal
55	≈ 55 kcal	≈ 1,320 kcal
60	≈ 60 kcal	≈ 1,440 kcal
65	≈ 65 kcal	≈ 1,560 kcal
70	≈ 70 kcal	≈ 1,680 kcal
75	≈ 75 kcal	≈ 1,800 kcal
80	≈ 80 kcal	≈ 1,920 kcal
85	≈ 85 kcal	≈ 2,040 kcal
90	≈ 90 kcal	≈ 2,160 kcal
95	≈ 95 kcal	≈ 2,280 kcal
100	≈ 100 kcal	≈ 2,400 kcal

Those figures help set guardrails for planning. Once you set your daily calorie needs, it gets easier to match intake to goals. The hourly view simply backs into the day-long picture and keeps expectations grounded.

Why The Number Shifts Day To Day

Quiet rest isn’t identical from hour to hour. A few steady nudges move the needle:

Body Composition

Muscle tissue uses more energy than fat tissue at rest. Two people at the same weight can show different hourly burns if one carries more lean mass. Over months, resistance training can raise lean mass, which trims the gap between “paper math” and your actual number.

Air Temperature And Clothing

When you feel chilly, your body spends a bit more energy on heat. A warm room tightens the range around the 1 MET mark. That’s why labs test BMR in a thermoneutral room.

Food, Caffeine, And Timing

Eating sparks the thermic effect of food for a few hours. Caffeine can nudge energy use upward for a short window. The 1 MET shortcut assumes a true rest window between meals and without stimulants.

Sleep, Stress, And Fidgeting

Short sleep and tension tend to raise fidgeting and small movements. Even toe taps add up over a long workday. The Compendium lists quiet sitting at ~1 MET and “sitting, fidgeting” above that baseline.

How To Get A More Personal Estimate

You can go beyond the 1 MET shortcut with a predictive equation that accounts for sex, age, height, and weight. In many clinics and sports settings, the Mifflin–St Jeor equation is the go-to for resting energy needs. It’s widely adopted and performs well across body sizes.

Use Mifflin–St Jeor

• Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
• Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

The result is kilocalories per day at rest. Divide by 24 to get an hour-by-hour view. This isn’t a lab measurement, but it often lands closer to reality than weight-only math for people at the edges of the chart (very short, very tall, or older adults).

Worked Example (Step By Step)

Let’s say a 35-year-old woman weighs 68 kg and stands 165 cm. Plugging into Mifflin–St Jeor gives about 1,410 kcal per day at rest. Dividing by 24 yields ~59 kcal per hour. The 1 MET rule would predict ~68 kcal per hour from weight alone. In practice, the personal estimate sits a bit lower here because age and height pull the number down.

Lab Testing, Apps, And Where They Differ

Apps and wearables estimate from inputs and movement data. They can trend well over time but don’t measure oxygen and carbon dioxide directly. A lab session with indirect calorimetry does. It tracks gas exchange while you rest in a controlled room, which gives a true reading for that day. Many research centers and some clinics offer this test. The NIDDK metabolic testing page explains the setup and the tools used.

For daily planning, the 1 MET rule and Mifflin–St Jeor cover most needs. Use them to set a starting point, then fine-tune with progress checks every few weeks.

Thermic Effect And Light Movement: Why Your Day Beats The Math

Even a “rest day” includes meals, steps, and chores. That’s why your 24-hour total climbs above the pure at-rest number. The Compendium pegs quiet rest at ~1 MET; short bouts like slow walking raise that to ~2–3 METs. You can see the range on the 1 MET standard page, which lists lying and sitting codes.

Practical Ways To Nudge Daily Burn

Small changes layer on top of your baseline. Pick two or three that fit your routine and track them for a month.

Factor	Expected Direction	Practical Tip
Lean Mass	Slightly up over months	Two to three strength sessions per week with progressive loads
Room Temperature	Cooler room edges up burn	Keep indoor temp in a comfy mid-range; avoid heavy layers all day
Meal Timing	Short bump after meals	Center meals on protein and fiber to stretch satiety and TEF
Caffeine	Small, short-term bump	Stick to moderate intake; skip late-day cups
NEAT (Fidgeting)	Up with more small movements	Stand for calls, walk the hallway, add micro-breaks
Sleep	Poor sleep skews appetite and activity	Set a repeatable sleep window and dim screens early

Turn The Math Into A Plan

Start with your hourly estimate and scale to 24 hours. Add a modest activity layer for steps and chores. Then set intake to match your target. If you’re dialing in weight change, a small daily gap works better than a big swing. That’s where a steady routine beats guesswork.

Simple Three-Step Setup

1. Pick your at-rest base: either weight × 1, or the Mifflin–St Jeor daily result ÷ 24.
2. Add an activity slice that reflects your week. Desk jobs tend to add a smaller slice; on-your-feet work adds more.
3. Track a few markers: scale trend, waist, and energy levels. Adjust by 100–200 kcal if progress stalls for two weeks.

Common Mistakes That Throw Off Estimates

Using Only Daily App Totals

Apps can drift if they overshoot steps or log workouts twice. Keep an independent check with the simple hourly method and compare.

Copying A Friend’s Numbers

Two bodies at the same weight may not match on burn. Age, height, and lean mass pull the lines apart. Use your own inputs for personal math.

Changing Too Many Things At Once

If you tweak sleep, workouts, and meals in the same week, it’s hard to know which lever moved the outcome. Tweak one lever, recheck in two weeks, then move to the next.

Worked Numbers You Can Reuse

Here are quick hourly estimates you can stash for planning. They’re based on the 1 MET rule and keep math easy during busy weeks.

• 55 kg → ~55 kcal per hour
• 62 kg → ~62 kcal per hour
• 68 kg → ~68 kcal per hour
• 75 kg → ~75 kcal per hour
• 82 kg → ~82 kcal per hour
• 90 kg → ~90 kcal per hour

When To Book A Measurement

A lab test is handy if your needs are clinical, you’re peaking for sport, or progress keeps stalling. Indirect calorimetry uses a mouthpiece or canopy to track oxygen in and carbon dioxide out while you rest in a quiet room. This gives you a measured baseline for that day, which you can bring back to your plan. If you go this route, ask the provider about prep steps: no hard training the day before, no food or caffeine for a few hours, and a calm room. You can learn more about the setup on the NIDDK metabolic testing page.

Bottom Line For Busy Weeks

Use weight × 1 to get your hourly burn at rest. If you want more precision, run Mifflin–St Jeor and divide by 24. Keep meals and movement steady for two weeks and check progress. Small, steady changes add up. If you want a deeper walkthrough, try our calorie deficit guide next.

References At A Glance

The 1 MET convention for quiet rest and the ranges for light activities come from the Compendium of Physical Activities. You can review the exact inactivity codes and their 1.0 MET entries on the Compendium 1 MET standard page. For measured testing methods and context, see the NIDDK metabolic testing overview.