Resting energy burn depends on age, sex, body size, and body composition; a simple formula gives a solid daily estimate.
Difficulty
Accuracy
Cost
Quick Estimate
- Plug height, weight, age, and sex into Mifflin–St Jeor.
- Pick a single set of inputs you can repeat.
- Good for day-to-day planning.
Basic
Smart Estimate
- Use Mifflin–St Jeor plus body-weight trend.
- Re-check measurements monthly.
- Refine with step count or activity logs.
Better
Clinical Test
- Measure REE with indirect calorimetry.
- Arrive fasted and rested.
- Best when precision matters.
Best
What “Resting Calories” Really Mean
When people ask about daily calories burned at rest, they usually want resting energy expenditure (REE) or basal metabolic rate (BMR). These are closely related. Both reflect the energy your body uses to run core functions like breathing, circulation, and cell maintenance while you’re not moving around. BMR is measured under stricter lab conditions; REE is more practical in clinics and research. In daily life, most calculators return a REE-style number.
The go-to way to estimate REE outside a lab is the Mifflin–St Jeor equation, which uses age, sex, height, and weight. It has strong performance in adults when compared with measured values from indirect calorimetry, the lab method that reads oxygen use and carbon dioxide output to quantify energy burn. Peer-reviewed comparisons place this equation among the better choices for healthy adults.
Daily Resting Calories: How To Estimate Yours
Grab a tape, scale, and recent age. Convert to metric if needed: kilograms for weight, centimeters for height. Then apply:
Mifflin–St Jeor (Adults)
Men: REE = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (y) + 5
Women: REE = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (y) − 161
These are estimates, not a diagnosis. Two people with the same stats can differ due to lean mass, hormones, medications, or genetics. Treat the result as a starting point you can tune with real-world outcomes.
Sample Resting Calories For Common Body Profiles
The table below shows example REE values using Mifflin–St Jeor for typical adult heights and ages. Use it to sanity-check your number. If your details sit between rows, your estimate will land between those values.
| Profile (Age • Height • Weight) | Sex | REE (kcal/day) |
|---|---|---|
| 25y • 160 cm • 60 kg | Female | 1,350 |
| 25y • 175 cm • 75 kg | Male | 1,750 |
| 35y • 165 cm • 70 kg | Female | 1,420 |
| 35y • 180 cm • 85 kg | Male | 1,870 |
| 45y • 170 cm • 80 kg | Female | 1,420 |
| 45y • 180 cm • 90 kg | Male | 1,850 |
| 55y • 165 cm • 75 kg | Female | 1,330 |
| 55y • 175 cm • 85 kg | Male | 1,720 |
Calorie planning clicks into place once you set your daily calorie needs. Use your REE as the anchor, then adjust based on movement and goals.
What Affects Your Resting Number
Lean mass: More muscle raises energy use at rest. Two bodies at the same weight can have different REE if one carries more lean tissue.
Age: Average numbers drift down with age due to shifts in body composition and hormone patterns.
Sex: Men trend higher than women at the same height and weight because of lean mass differences.
Medications and conditions: Thyroid status, fever, some drugs, and acute illness can move the needle.
From Resting Calories To A Full-Day Picture
Rest values alone don’t tell the whole story. To map out daily burn, you’d multiply REE by an activity factor. That turns “resting” into a full-day estimate that accounts for steps, chores, and training. The multipliers below are widely used in coaching and clinical settings.
Common Activity Multipliers
The Mifflin–St Jeor equation comes from a peer-reviewed study in the American Journal of Clinical Nutrition. Pairing its REE estimate with a suitable activity factor gives a practical full-day number you can test against your weight trend.
| Activity Level | Multiplier | Use Case |
|---|---|---|
| Sedentary | 1.2 | Desk job, low steps |
| Lightly Active | 1.35 | Regular walks, light chores |
| Moderately Active | 1.5 | 3–5 training sessions per week |
| Very Active | 1.7 | Daily training or physical work |
| Athlete-Level | 1.9 | Two-a-day sessions or heavy labor |
Picking The Right Multiplier
Use steps as a quick cue. Under 5,000 steps tends to feel sedentary. Around 8,000–10,000 slots into light to moderate. If most days include planned workouts that raise your heart rate, move up a notch. The Adult Compendium of Physical Activities lists MET values for hundreds of tasks and can help you sanity-check where you land.
How To Tighten Your Estimate Over 2–4 Weeks
Numbers are a starting point. Real-world tracking turns them into a good fit. Here’s a simple method that works:
Set Your Baseline
Pick an REE estimate. Apply an activity factor. Eat near that target for 14 days. Log weight at the same time each morning after using the bathroom. Average the first three days and the last three days to smooth out water shifts.
Read The Trend
If weight holds steady within a small band, your estimate is close. If you’re down roughly 0.2–0.5% of body weight per week without trying, you’re running a deficit. If you’re up at a similar pace, you’re in a surplus.
Adjust In Small Steps
Move intake by 150–250 kcal and hold for another 10–14 days. Keep training and daily steps consistent while you test, or the signal gets noisy.
When A Lab Test Makes Sense
Indirect calorimetry measures resting energy directly from gas exchange while you lie quietly under a hood or wear a mask. Clinics use it for patients with medical conditions, athletes in tight weight classes, and anyone who needs a precise baseline. University labs and some hospitals offer appointments. A typical session takes 10–20 minutes and requires fasting and rest beforehand.
A hospital guide from Brigham and Women’s explains the process and typical ranges for adults in clear terms; see this indirect calorimetry explainer.
Practical Examples You Can Copy
Quick Math For A 70 kg, 170 cm, 30-Year-Old Woman
REE = 10×70 + 6.25×170 − 5×30 − 161 = 700 + 1062.5 − 150 − 161 = 1,451 kcal/day. With light activity, daily burn lands near 1,451 × 1.35 ≈ 1,960 kcal/day. Hold that intake steady for two weeks and read the trend.
Quick Math For An 85 kg, 180 cm, 40-Year-Old Man
REE = 10×85 + 6.25×180 − 5×40 + 5 = 850 + 1125 − 200 + 5 = 1,780 kcal/day. With moderate training, daily burn lands near 1,780 × 1.5 ≈ 2,670 kcal/day.
Common Mistakes That Skew Resting Numbers
Mixing Up Units
Plugging in pounds for kilograms or inches for centimeters throws off the equation. If your result looks off by a factor of two, double-check units.
Chasing Day-To-Day Swings
Water shifts from salt, fiber, or menstrual phase can swing scale readings. Use weekly averages before you change targets.
Changing Too Many Variables
Dial in intake first. Keep training, steps, and sleep steady while you test. Adjust one lever at a time so you can read the signal.
How This Ties To Eating Plans
Resting burn sets the floor. From there, you pick a calorie target that matches your goal and food preferences. Government guidance collects calorie patterns by age and sex to help people build meals at common calorie levels. That context helps when you’re sketching a weekly plan around your number.
Simple Way To Turn REE Into A Daily Target
- Estimate REE with Mifflin–St Jeor.
- Choose an activity factor that matches your typical week.
- Set intake to that full-day number for two weeks.
- Adjust by 150–250 kcal based on the trend you see.
FAQ-Style Clarifications, Without The FAQ Block
Is REE The Same As BMR?
They’re siblings. BMR has stricter lab rules. REE is measured under relaxed conditions. For planning, people use REE estimates because they align with real life.
Can Wearables Replace An Estimate?
Wrist devices guess energy burn from heart rate and movement. Some people get decent ballpark numbers; others see drift. Use them as a trend tool, then ground your plan in weight-trend feedback.
Do You Need Body Fat Percentage?
It helps if you want a fine-tuned plan, since lean mass drives resting burn. You can still plan well with weight, height, age, and sex alone.
Build A Plan Around Your Number
Once you have a steady estimate, you can set breakfast portions, pick smarter snacks, and match your grocery list to your target. If you prefer a habits-first route, start by logging protein, produce, and steps. Many readers find calorie targets easier to follow once they nail a few habit anchors.
Want a full walkthrough of daily targets and examples? Try our calorie deficit guide for a tidy method.