Calculator for TDEE using REE

Here's a calculator that uses REE to determine TDEE. It was still really close to other calculators(2340 vs 2390)

http://calorieline.com/tools/tdee

It has a great explanation of weight drift/plateaus, too.

Consider Mary. She has hit her target weight of 130 pounds many times over the years, but always winds up floating back up to 150 lbs. The weight always comes back slowly but surely. Why? Mary always loses weight the same way, with her trademark system of exercise 5 days a week, skipping lunch, and not eating anything after 7pm. Eventually, she hits 130 lbs, and she starts to celebrate and relax. She's earned it.

Mary is 42 year old, stands 5 feet and 6 inches tall, and gets a moderate amount of exercise each week. When she's not on a diet, she eats about 1900 calories each day on average. A tad high for her height and the amount of exercise she gets, but really not too bad. Now that she's lost her 20 lbs, she wants to go back to her normal habits. Mary assumes that it is the occasional binge, or overly festive weekend, that typically causes her to put her weight back on. She only needs to binge a little less often, and she'll be fine, right? Wrong. Mary, at her height and age, should be getting about 1750 calories each day if she is going continue her moderately active lifestyle, and she is averaging 1900. Those extra 150 calories per day may not seem like much, but they are consistent with being 150 pounds. That is, her "Total Daily Energy Expenditure" (TDEE) is not that of a 130 pound person who exercises moderately -- those extra 150 calories per day add up to the TDEE of a 150 pound women of her height and age and exercise routine. Because of this, her weight will slowly but surely creep back up. Conversely, if she were to start out at 170 pounds (maybe due to an unusually indulgent Christmas season), her weight would simply drift down to 150 pounds. One way or another, given Mary's height, weight, age, and exercise level, her weight will just settle at about 150 pounds if she eats 1900 calories per day. That is the real meaning of TDEE.

Jump forward 6 months. Mary has put the weight back on. She is now back to 150 pounds. But she's grown tired of her trademark diet, and decides to go hunting around the web for a new diet -- one that lasts. Along the way she discovers TDEE. After playing around with the BMR and TDEE calculator on a certain web site, she discovers that to maintain a weight of 130 pounds, at her age and height and exercise routine, she would have a TDEE of 1745 calories per day. Mary decides that she is not ready to do her regular hard-core diet yet, but she is willing in the interim to limit herself to 1745 calories per day, just to get in the habit. It's only 150 calories. She starts tracking her calories on a certain, awesome web site, develops her calorie-counting skills, and sets a target date for starting her diet in a couple of months.

Alas, Mary is not able to get all the way down to 1750 calories per day, instead averaging about 1800. But a funny thing happens -- Mary's weight starts to drift down anyway. The scale does not lie. What is happening? By eating 1800 calories per day, Mary adopted the TDEE profile of a 5'6", 42 year old female of 140 lbs who exercises at a moderate level. At 1800 calories per day, Mary's body could not sustain a weight of 150 pounds, and began to drift down, slowly but surely towards 140 lbs, where it would eventually level off. If mary went on a diet, dropped all the way down to 130, but then resumed eating 1800 calories per day, her weight would then drift up to 140. Diets are temporary -- TDEE is for good.

After tracking her calories for a few months, Mary discovers that over the long term, it's going to be hard to eat less then 1800 calories per day on average. Sure, she can go a few days at 1700, or even less, but then she always breaks down with a little splurge. When she looks at her monthly averages, they always wind up at about 1800. That seems to be as low as it goes for her when she is not dieting. So now what? Oy, another diet is coming on. But then Mary remembers TDEE, and that there are two 'sides' to TDEE equation -- calories eaten, but also calories burned. Mary realizes that if she can increase her exercise so that that it amounts to an extra 50 calories per day, on average, then her TDEE will be consistent with that of a 130 pound woman, and her weight will drop. And so she does just that. And her weight drifts down.

Mary may not realize it at first, but with that small adjustment, she just got off the diet roller coaster. Having played around with her caloric intake, making minor adjustments, and with a little help from the TDEE calculator, she has zeroed in on a regime that works for her. She no longer thinks in terms of diets, but in terms of what her average number of calories and average amount of exercise need to be to hit her weight (in other words, what her TDEE should be). She knows that if she gets enough exercise, then she gets to have about 1800 calories per day. It does not matter whether her weight starts at 120 pounds or at 150 pounds -- regardless, her weight will simply drift towards 130 pounds.