Ever wondered how many calories that walk, run, or gym session actually burned? The answer depends on three things — your weight, how long you exercised, and how intense the activity was. This guide explains how calorie burn is calculated, what MET values are, and roughly how much different activities burn. For instant numbers, use our free Calories Burned Calculator.

How Calorie Burn Is Calculated

The standard, science-based method uses MET values:

Calories = MET × weight (kg) × time (hours)

For example, running at 6 mph (MET 9.8) for 30 minutes at 70 kg burns 9.8 × 70 × 0.5 ≈ 343 calories. The formula is simple, consistent, and works for any activity with a known MET value.

What Are MET Values?

MET stands for Metabolic Equivalent of Task. One MET is your energy use at rest; an activity rated at 8 METs burns about eight times as much. As a guide: 1–3 METs is low intensity (slow walking, yoga), 3–6 METs is moderate (brisk walking, easy cycling), and 6+ METs is vigorous (running, fast cycling, competitive sport).

Calories Burned by Activity (30 minutes, 70 kg)

• Walking (brisk, 3.5 mph): ~150 calories
• Football / soccer: ~245 calories
• Cycling (moderate): ~263 calories
• Swimming (moderate): ~203 calories
• Running (6 mph): ~343 calories
• HIIT / circuit training: ~280 calories

What Affects How Many Calories You Burn?

• Body weight: heavier bodies use more energy for the same activity.
• Intensity & duration: harder and longer burns more.
• Fitness & muscle: more muscle raises your energy use.
• Conditions: hills, sand, wind, and heat all add to the cost.

How It Fits With Your Diet

Calories burned through exercise is only one side of the energy equation; what you eat is the other. If your goal is weight management, it helps to know both your daily needs and your activity burn — but exercise estimates are approximate, so focus on consistency and trends rather than chasing an exact number. To see your daily needs, use our Calorie Calculator and TDEE Calculator. For any significant diet or training change, a doctor or registered dietitian is the best guide.