BMR & TDEE Calculator

Calculate your Basal Metabolic Rate and daily calorie needs with goal-based targets. All calculations are done locally in your browser.

Your Metabolism Dashboard

Choose your units, formula, and activity level. Then calculate your BMR and TDEE targets.

What this tool can do

This calculator is designed to give you a complete daily calorie picture—not just one number.

Why you need this tool

Calories are easier to manage when you know your maintenance baseline. This tool helps you avoid guessing and gives you targets you can actually act on.

Technical terms explained

Other Health Tools

Technical FAQ

Which formula should I use for the most accurate BMR?

For most people, Mifflin-St Jeor is the modern default. If you know your body fat %, Katch-McArdle can be useful because it estimates based on lean mass.

Why does TDEE change so much when I switch activity levels?

TDEE is calculated as BMR × Activity Multiplier. Changing from 1.2 to 1.55 (or higher) represents a large difference in daily movement and training volume, so the final calorie estimate shifts accordingly.

Do the weight loss targets guarantee 0.25 kg/week or 0.5 kg/week?

No. The -250 and -500 targets are simplified daily deficits. Real results depend on adherence, tracking accuracy, water retention, and how your body adapts over time.

What does “client-side processing” mean here?

All calculations run in your browser using JavaScript. Your inputs are not sent to any server and no external APIs are used for calculation.

Why does Katch-McArdle require body fat percentage?

Katch-McArdle calculates BMR from Lean Body Mass. Without body fat %, the tool can’t estimate lean mass, so it can’t compute that formula reliably.