Kefiw

Archived noindex page. Kefiw's public focus is Property decision help.

Archived page

This older Kefiw page is kept for reference, marked noindex, and removed from the primary sitemap. The current Kefiw experience is focused on property decisions: cost, quotes, damage, buying, selling, owning, and packets.

Go to Property

MET Calorie Burn Guide

The academic method underneath every fitness tracker's calorie number.

MET × 3.5 × bodyweight_kg / 200 × minutes gives kcal burned for any activity catalogued in the Compendium of Physical Activities.

MET is the multiplier of resting oxygen consumption an activity demands. Sitting at 1.0 MET consumes ~3.5 mL O2 per kg per minute. Running at 9.8 MET consumes ~9.8× that. Ainsworth's Compendium of Physical Activities (2011) catalogued several hundred activities with MET values calibrated against indirect calorimetry. That catalogue is the academic reference underneath every Fitbit, Apple Watch, and Strava calorie number — plus accelerometer data for real-time intensity modulation.

Part of: Structural Output

Quick answer

MET × 3.5 × bodyweight_kg / 200 × minutes gives kcal burned for any activity catalogued in the Compendium of Physical Activities.

What you are trying to do
The academic method underneath every fitness tracker's calorie number.
Limit to remember
Treat this as a practical aid for the task, not a replacement for professional judgment.

Key points

  • Formula: kcal = MET × 3.5 × weight_kg / 200 × minutes. The 3.5 is mL O2 per kg per minute at 1 MET; 200 converts to kcal.
  • Common METs: sleeping 0.9 · sitting 1.3 · walking 3mph 3.3 · cycling 12-14 mph 8.0 · running 6 mph 9.8 · running 8 mph 11.8 · swimming laps 7.0.
  • Accuracy vs indirect calorimetry is ±15%. Individual mechanical efficiency is the largest error source — the same 9.8 MET run burns 15% more in an inefficient runner.
  • MET values are roughly independent of bodyweight — heavier people burn more absolute kcal at the same MET because the multiplier runs through kg in the formula.
  • Session kcal, kcal/h sustained, and food-equivalent framings (Big Macs, donuts) help translate the number into daily-life intuition.
  • Above 10 MET the relationship becomes less linear — elite-intensity work needs interval-specific calorimetry rather than the MET multiplier.

How to

  1. Pick the activity that most closely matches the Compendium entry — "moderate cycling" differs from "vigorous cycling" by 3+ MET.
  2. Enter duration in minutes (calibrated for steady-state; subtract warm-up/cool-down for sprint workouts).
  3. Read session kcal, sustained kcal/h, and the junk-food equivalent for intuition.
  4. For mixed sessions, split by MET: 10 min warm-up at 4 MET + 30 min threshold at 10 MET + 10 min cool-down at 4 MET.
  5. Cross-check weekly totals against weight change — real-world expenditure is the audit for formula accuracy.

Examples

  • 180 lb (82 kg) · 30 min running 6 mph (9.8 MET)
    kcal = 9.8 × 3.5 × 82 / 200 × 30 ≈ 422 kcal session · ~844 kcal/h sustained · ~0.71 Big Macs burned.
  • 150 lb (68 kg) · 60 min moderate cycling (7.0 MET)
    kcal = 7.0 × 3.5 × 68 / 200 × 60 ≈ 500 kcal. Same bike ride, 220 lb rider: ~730 kcal — 46% more.
  • 200 lb (91 kg) · 45 min yoga (2.5 MET)
    kcal = 2.5 × 3.5 × 91 / 200 × 45 ≈ 179 kcal. Low-MET activities burn less than intuition suggests.

When to use which tool

▸ Operational Thresholds
  • CYAN · STABLEUnder 3 MET — light activity (walking, cooking, office work); maintenance-level expenditure.
  • GOLD · GUARDED3-6 MET — moderate activity (brisk walking, light cycling, recreational sport); target zone for general health guidelines.
  • MAGENTA · CRITICAL6+ MET — vigorous activity (running, lap swimming, hard cycling); drives aerobic fitness and meaningful kcal expenditure.
▸ Pivot
Expenditure mapped. Reset the metabolic floor your training deficit or surplus sits on.
Metabolic Floor · BMR / TDEE →

Related

Frequently asked questions

How accurate is MET vs a chest-strap HR monitor? Comparison

Similar — both land ±10-15% vs indirect calorimetry. HR-based estimates fail in strength training and cold-weather cardio where HR is decoupled from work rate. MET works from activity type, so it is steadier in those cases.

Do fitness trackers really use MET?

Under the hood, mostly yes — plus accelerometer data to modulate intensity and detect activity type automatically. Apple Watch additionally uses personalised calibration from recent workouts, which narrows the error band to ±5-8% for users with months of history.

Why do I burn fewer calories than my watch says? Troubleshooting

Wearables tend to over-estimate by 10-30% on walking and everyday activity, and the bias compounds across weeks. Match watch output against weight-trend math before trusting it as a diet input.

How should I use this guide with a Kefiw tool? How-to

Use the guide as the plan and the linked Kefiw tool as the check. Read the steps first, try the move manually, then use the tool to compare outputs, catch edge cases, and decide whether the result actually fits your task.

What mistake do tool guides help avoid? Troubleshooting

Tool guides help avoid using a utility mechanically without understanding what you are trying to accomplish. Most word, writing, and text utilities are fast, but speed can hide context mistakes. Know whether you are solving a puzzle, cleaning copy, drafting a line, or checking a rule.