What this site is for

There are a lot of spammy sites out there claiming to help you find your TDEE. This site was created solely to show and explain what this value is, and to do it for free without any ads. We also cite where each figure comes from, and have a research section below. If you think you've found a mistake in the research or calculations here, please let us know.The point of Free TDEE is to allow you to calculate your TDEE easily, while getting an explanation of where each number comes from.I am planning on a complete write up of how this was made and the thoughts behind it, which you'll be able to read on my Substack.

Basal Metabolic Rate

BMR on Free TDEE is calculated using the Mifflin-St Jeor equation, as first described in their 1990 landmark paper.The equations given in that paper are separated out between men and women.There exist other formulas for BMR that may prove to be more accurate, but they require additional info that can be hard to come by. One of these equations is the The Katch–McArdle formula, which incorporates your % of lean body mass into the equation too.

Research

New TDEE Research

Recent research we like, with links and a snapshot of their abstract.

Effects of Varying Protein Amounts and Types on Diet-Induced Thermogenesis

Dec 2024

The purpose of this meta-analysis was to compare the impact of isocaloric meals/diets containing different amounts or types of protein on energy metabolism. Databases were searched in June 2024 for studies that compare DIT or total daily energy expenditure (TDEE) in response to isocaloric acute meals or longer-term diets containing different amounts or types of protein. There was no evidence that different types of protein impacted energy metabolism. Higher protein meals/diets increase components of energy expenditure.

What's in that number

How did we calculate your TDEE? Well, it starts by calculating your Basal Metabolic rate (how many calories you use just by being alive) and your Non-exercise Activity Thermogenesis (all the tiny bits of movement that are outside of exercise). This gives you your non-variable calorie expenditure:

Getting even more granular

Your NEAT and BMR are usually good enough to give you a good estimate of how many calories you're burning in a typical day. But if you want a truly complete picture, you might want to include your TEF (The Thermic Effect of Food) and EEE (exercise energy expenditure) as well. Your estimates of your activity level in NEAT are already helping to account for a typical day's activity level, but some would prefer to add calories specifically burned during exercise as well. Our calculator assumes anywhere between 0 and 600 calories from exercise. But your actual exercise expenditure is likely to vary a lot.Similarly, you're actually burning calories every time you eat/digest food. The TEF calculation adjusts for that. We (and many other resources) use an assumption that around 10% of your food calories are going to be used in digestion. This too is set as a constant on freeTDEE. Our calculator assumes you will be eating around your BMR + NEAT, plus or minus 500 calories. Again, in reality, this can vary a lot, and calorie estimates from food are natoriously inaccurate.