TDEE.io is a free online TDEE calculator that estimates your Total Daily Energy Expenditure (TDEE) using the Mifflin–St Jeor equation to provide maintenance calorie targets based on your age, sex, height, weight, and activity level.
What is TDEE.io?
TDEE.io calculates your Total Daily Energy Expenditure by first estimating your Basal Metabolic Rate (BMR) using the validated Mifflin–St Jeor equation, then applying an activity factor to produce your daily maintenance calories. You input age, gender, height (in feet/inches), weight (in pounds), and activity level (sedentary through athlete). The tool outputs your maintenance calorie number along with practical targets for calorie deficit (weight loss) and calorie surplus (muscle gain). It runs entirely in your browser with no account required.
Key Features
- Mifflin–St Jeor BMR calculation — Uses the peer-reviewed equation from a 1990 study to estimate resting metabolic rate instead of generic formulas.
- Five activity levels — Choose from Sedentary, Light Exercise, Moderate Exercise, Heavy Exercise, or Athlete to match your actual daily movement.
- Imperial unit input — Enter weight in pounds and height in feet/inches; the tool handles the conversion behind the scenes.
- Instant calorie targets — After entering your stats, you immediately see maintenance calories plus suggested deficit and surplus amounts.
- No sign‑up required — The calculator is completely free with no account creation, email collection, or usage limits.
- Responsive design — Works on desktop and mobile browsers, with a clean single-page layout that avoids clutter.
Who is it for?
- People new to calorie tracking — Get a science‑backed starting point for daily calorie intake without needing to learn complex equations or use separate BMR calculators.
- Dieters aiming for fat loss — Use the displayed deficit target to set a daily calorie goal that creates a sustainable calorie gap while preserving energy for daily activities.
- Athletes and lifters seeking muscle gain — Refer to the surplus recommendation to plan a controlled calorie increase that supports muscle growth without excessive fat gain.
What can you do with TDEE.io?
- Plan a weight‑loss diet — Note the maintenance calorie estimate, then subtract the suggested deficit target to set a daily eating limit that aligns with your activity level.
- Set a bulking calorie goal — Use the surplus recommendation to add the right number of calories to your maintenance number, adjusting over time based on real progress.
- Compare activity levels — Re‑run the calculator with different activity multipliers to see how increasing exercise frequency changes your daily calorie needs.
How does it work?
- Select your preferred unit system (Imperial is default).
- Enter age, gender, weight (in pounds), and height (in feet/inches).
- Pick an activity level that best describes your typical weekly exercise.
- Click Calculate TDEE – the tool shows your daily maintenance calories, plus deficit and surplus targets, all derived from the Mifflin–St Jeor BMR equation.
Pricing
TDEE.io is completely free to use with no premium tiers, payment requirements, or hidden limits.
FAQ
Is TDEE.io free?
Yes. The calculator has no cost, no registration, and no usage caps. All features (BMR calculation, activity adjustments, calorie targets) are available without payment.
What equation does TDEE.io use?
It uses the Mifflin–St Jeor equation, which is a peer‑reviewed formula for estimating BMR based on sex, age, height, and weight. The equation is referenced directly on the page with a link to the original PubMed study.
What inputs do I need to provide?
You need age, sex (male/female), weight in pounds, height in feet and inches, and a selection from five activity levels ranging from Sedentary to Athlete.
