We’ve had a couple questions about our TDEE calculator, how we get the numbers and why different TDEE calculators give you different numbers.
First, TDEE is “total daily energy expenditure” and is simply an approximation of the average amount of calories you use over a day. Second, here is a link to our TDEE calculator. 🙂
There are a couple of different factors in the TDEE – the BMR (basal metabolic rate – your basic metabolism, ie the energy required to keep you alive) and the “activity factor”. The BMR can be calculated a number of different ways. We use the Mifflin-St Jeor equation as it has been shown to be the most accurate.
TDEE is the BMR scaled by the activity. It generally goes between 1.2 (sedentary) and 1.9 (hard sustained exercise every day or more often) and scales linearly. The differences I’ve seen in various calculations with this usually have to do with the exact wording of each point – this can lead people to choose a higher or lower number and, sometimes, more activity factors in between the ones we have, eg 8 choices instead of the 5 we have.
The things to check on different websites are:
1 – which BMR equation they’re using
2 – that you’re comparing like with like (i.e. choosing the same activity level for both). Our activity level descriptions tend to lead people to the lower number – this is deliberate as most people here are trying to lose weight (and tend to overestimate the amount of exercise they do… or at least I do.)
The best way to think of TDEE is an estimate. Neither TDEE nor calorie counts can be exact, but both are extremely useful in losing weight, maintaining weight and gaining weight (depending on what you want to do!).
4:33 pm
24 Jun 14