Calories Burned Calculator

How Many Calories Does Your Workout Really Burn?

Gym machines lie. That treadmill saying you burned 500 calories? It's probably 30–40% too high. The watches and fitness trackers? Overestimate by 20–90% depending on the brand and activity.

The most reliable method scientists have for estimating calorie burn is MET values — Metabolic Equivalents of Task. MET is a standardised measure of how much energy an activity costs compared to sitting still. Walking at 3 mph is about 3.5 METs (3.5 times your resting burn). Running at 6 mph is about 10 METs. Sitting on the sofa is 1 MET.

This calculator uses the Compendium of Physical Activities — a research database maintained by Arizona State University that catalogues MET values for over 800 activities. It's the same source used by the NHS, WHO, and most fitness research.

Calories Burned by Activity (Per 30 Minutes)

This reference table shows approximate calories burned during 30 minutes of common activities for a 70 kg (154 lb) person. Your individual burn depends on your weight — heavier people burn more.

What this means for you: A 30-minute jog burns roughly the same as a pint of beer (200 calories). Two biscuits with your tea equals about 20 minutes of swimming. These comparisons aren't meant to make you feel guilty about food — they're to give you realistic expectations about exercise as a weight management tool.

The Afterburn Effect (EPOC): Extra Calories After Your Workout

When you finish a hard workout, your calorie burn doesn't stop immediately. Your body continues burning extra calories for hours afterwards — repairing muscle tissue, replenishing energy stores, and returning to its resting state. This is called Excess Post-Exercise Oxygen Consumption (EPOC), or the "afterburn effect."

How much extra? It depends on intensity. A light 30-minute walk produces negligible EPOC. A hard HIIT session or heavy weight training workout can elevate your metabolism by 50–200 extra calories over the next 24–48 hours.

The practical takeaway: High-intensity exercise and strength training burn more total calories than steady-state cardio — not just during the session, but for hours after. This is one reason why weight training is so effective for fat loss, even though the calorie burn during the workout itself looks lower than running.

Why You Shouldn't Use Exercise to "Earn" Food

The "I ran 5K so I can have pizza" mindset is one of the most common traps in fitness. Here's why it doesn't work:

A 5K run burns roughly 300–400 calories. A medium Domino's pizza has about 2,000 calories. You'd need to run a half marathon to "earn" that pizza. The maths simply doesn't support using exercise as a licence to eat freely.

Exercise is brilliant for health, fitness, mood, sleep, and muscle building. But for pure weight management, your diet does the heavy lifting. Use our TDEE Calculator to find your daily calorie target and our Macro Calculator to plan your nutrition. Let exercise be the bonus, not the foundation of your calorie budget.

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