calories burned at rest calculator

What does “calories burned at rest” mean?

Calories burned at rest are the calories your body uses to stay alive and functioning, even when you are not exercising. This includes breathing, circulating blood, supporting brain activity, regulating body temperature, and basic cellular processes.

In nutrition and fitness, this number is often called BMR (Basal Metabolic Rate) or RMR (Resting Metabolic Rate). The two are very similar. RMR is typically measured under less strict lab conditions, so most practical calculators use RMR-style estimates.

How this calculator works

This calculator uses the Mifflin-St Jeor equation, one of the most widely used formulas for estimating resting calorie burn:

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

Your result is an estimate of calories burned per day at rest. We also show approximate calories burned per hour and per minute.

How to use your result

1) Start with your resting calories

Your resting calorie number is a baseline. It is not your total daily calorie burn unless you are fully at rest all day.

2) Estimate total daily calories

Real life includes movement, digestion, and exercise. Many people estimate total daily energy expenditure (TDEE) by multiplying resting calories by an activity factor:

• Sedentary: RMR × 1.2
• Lightly active: RMR × 1.35
• Moderately active: RMR × 1.5
• Very active: RMR × 1.7+

3) Choose a goal

• Fat loss: Eat below estimated TDEE (often 300–500 calories/day deficit).
• Maintenance: Eat near estimated TDEE.
• Muscle gain: Eat slightly above TDEE (often 150–300 calories/day surplus).

What affects calories burned at rest?

Resting energy expenditure varies between people. Common drivers include:

• Body size: Larger bodies generally burn more calories at rest.
• Lean mass: More muscle mass raises resting calorie burn.
• Age: Resting metabolism often decreases with age.
• Sex: Average differences in body composition influence RMR.
• Hormones and health status: Thyroid function, illness, and medications can change metabolism.
• Sleep and stress: Poor sleep and chronic stress can indirectly impact energy balance.

Example

Suppose a 35-year-old woman is 165 cm tall and weighs 68 kg:

RMR = (10 × 68) + (6.25 × 165) − (5 × 35) − 161
RMR = 680 + 1031.25 − 175 − 161 = 1375 calories/day (approx.)

That means her body burns roughly 1,375 calories per day at rest, before accounting for daily activity and exercise.

Common mistakes when using metabolic calculators

• Confusing RMR/BMR with total calories burned in a day.
• Using outdated body weight after recent weight change.
• Not adjusting intake after progress stalls.
• Ignoring activity outside workouts (walking, standing, job movement).
• Treating estimates as exact lab measurements.

Tips for better accuracy over time

• Recalculate every 4–8 weeks as body weight changes.
• Track weekly weight trends, not just day-to-day fluctuations.
• Pair calorie targets with protein, fiber, hydration, and sleep habits.
• Use consistent weigh-in conditions (same scale, same time of day).

FAQ

Is this the same as a TDEE calculator?

No. This page estimates calories burned at rest. TDEE adds movement, digestion, and exercise on top of resting needs.

Can I lose weight by eating below this number?

Eating below resting calories can be difficult to sustain and may not be ideal for performance or hunger control. Most people set a moderate deficit from estimated TDEE instead.

How accurate is this calculator?

It is a practical estimate, not a diagnostic test. Individual variation can be meaningful, so use your real-world results (weight trend, energy, appetite, training) to fine-tune your plan.

Disclaimer: This calculator is for educational purposes and is not medical advice. If you have a health condition, are pregnant, or are managing a metabolic disorder, consult a qualified clinician or registered dietitian.