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Equation for calculating calories (lose 10 lbs in 6 weeks)

I found this in the 12/04 issue of Fitness magazine and thought it was interesting. It takes into account a person's age, height, and activity level. By using your goal weight (10 pounds lighter) in the equation, you automatically eat fewer calories. I'm not sure how accurate it is but at least it gives us an idea of what might be appropriate. Of course, losing 10 pounds in 6 weeks might be a little drastic for some people.

1. Subtract 10 pounds from your current weight, then multiply this by 4.4. (Ex. If you weigh 145 now, subtract 10 to get 135. Multiply 135 by 4.4 to get 594.)

2. Calculate your height in inches, then multiply by 4.6. (Ex. 5'4" is 64 inches. Multiply 64 by 4.6 to get 294.4.)

3. Multiply your age in years by 4.7. (If you're 30 you get 141)

4. Add up the answers to the first three steps and then add 655. (Ex. 594 + 294.4 + 141 + 655 =1684.4. Round up or down to the nearest whole number: 1684.

5. Multiply this number by an activity factor. These are the extra calories needed to support your daily physical activity level.
1.2 if you sit at a desk all day, unable to work out due to injury, or
too tired/busy to work out on a daily basis.
1.3 if you walk your dog twice or more daily, take the stairs whenever
you can or exercise moderately for up to 2 days a week.
1.5 if you exercise for 1 hour at least 3 and up to 5 times a week.
1.7 if you are a hard-core runner, train 2-plus hours a day or have a
physically demanding job.

Your final number equals your daily calorie limit to lose 10 pounds in six weeks.

Tue. Mar 28, 1:22pm

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Thanks for posting - Im always looking for new ways to calculate what my calories should be since I feel like I've just kind of guessed at it.

I wonder, though, how accurate this equation is. I did it and my calorie limit was 2117. That seems awfully high, given that right now I'm targeting around 1600 cals per day. And I used a physical activity level factor one lower than I thought described me, in case I was overestimating.

Tuesday, March 28, 2006, 3:03 PM

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thanks, this is really helpful!

Tuesday, March 28, 2006, 3:15 PM

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that would put ne at 2928 calories....that seems rather high im 41 195 lbs 5'3" and work out everyday for 1 1/2 hours

Tuesday, March 28, 2006, 3:48 PM

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It think it overestimates or possibly is the calories needed to maintain weight? Mine came out to be 2524, I actually think I would gain weight if I ate that much. My trainer has me on at 1400 calorie diet and I workout 6 times a week. I have about 10 pounds to lose.

Tuesday, March 28, 2006, 3:58 PM

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This makes no sense - so a 100 yr old gets to eat 300 more cals than a 20 yr old??? Surely you burn more when you're 20 and still kinda growing a little.

Tuesday, March 28, 2006, 4:18 PM

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There's absolutely no way this equation is accurate. I would never lose weight on 2635 calories/day!

Tuesday, March 28, 2006, 4:42 PM

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I'm not too sure of that either. It puts me at 2,658.6. I know if I eat that much, I will gain weight.

Tuesday, March 28, 2006, 5:15 PM

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Get your metabolism tested!!!

Best thing to do is get your metabolism tested! Once the machine figures your RMR (Resting metabolic rate) you can plug in your goal weight and how long you have to reach that goal and you get a handy dandy report that tells you how many calories to eat based on YOUR RMR, lifestyle and exercise.

Tuesday, March 28, 2006, 6:43 PM

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It gave me 1989, and I'm 23, activity factor of 1.3, and 120 lbs. I eat about 1300 calories a day, maybe 1500 on splurge days, and have been maintaining for quite awhile! Upping the calories by 700 a day couldn't possibly make me lose! Though I'd love to try!

Wednesday, March 29, 2006, 5:10 PM

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Can I recommend an alternative formula?

I've found this to be pretty dead-on over the years:

1. Multiply your current weight by 11. Those are the cals to maintain.
(i.e: 172 x 11 = 1,892 cals).

2. If you want to lose 10 lbs., that's 35,000 cals.

3. Subtract a cal minimum, like 1200, from the maintenance cals. Multiply by the amount of time you have to lose (6 weeks = 42 days).
(i.e: 1,892-1,200= 692.....692 x 42 = 29,064 cals burned through cal reduction!).

4. Subtract 35,000 (the amt. of cals in 10 lbs.) from the cals lost through cal reduction, to get the amt. that must be burned through exercise.
(i.e: 35,000-29,064= 5,936.)

5. How many times will you work out? Say 3x a week for 6 weeks-- that's 18 workouts. 5,936 divided by 18, is 330 cals that should be burned during each workout.

You can plug in a different daily limit, like 1500 instead of 1200, if 1200 is too low for you. But you shouldn't go below 1200 cals.
Hope that's helpful!

Thursday, March 30, 2006, 8:35 AM

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The formula doesn't work for small people. I'm 5' and 108, and using this formula, my maintenance caloric limit is 1188. That's already under 1200. Is it okay for small people to go under 1200/day?

Thursday, March 30, 2006, 10:18 AM

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The formula is intended for weight loss. I'm not sure if at 5' you want to be under 108...?
Multiplying by 11 takes into account a low activity level. If you're already active, you'd have to mulitply by 12. That'd put you at 1,296.
Otherwise, you'd have to stick to 1200 cals and then exercise to create the deficit you're looking for. Makes sense, since as you get closer to our goal, weight loss slows, since there's less to burn off.

Thursday, March 30, 2006, 11:49 AM

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The original formula posted seems way off to me. What scientific or mathematical evidence was presented to support this? Mine came out to like 2500 calories or something ridiculous like that.

The second formula (multiply current weight by 11 to maintain) seems more accurate, but again, where is the evidence that this is appropriate?

Thursday, March 30, 2006, 3:18 PM

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Although those seeking certifications in personal training do not dispense nutritional advice, national certification classes also inculde a nutritional component. That's where I got the second formula. I was a certified trainer for several years.

Thursday, March 30, 2006, 9:24 PM

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Here's a good calorie calculator from the Mayo Clinic. It pretty accurately nailed my daily maintenance calories at about 1600 calories per day.


Friday, March 31, 2006, 2:38 PM

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this depends way too much on the person. If you drink water, eat just greens and some carbs and a little good fat, you can lose a ton and not faint. But who wants that?

Saturday, May 12, 2007, 10:30 PM

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I think that my number was high too. Mine was 2413.2. I will try it and see how it works.

Saturday, May 12, 2007, 11:45 PM

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how much does counting calories really factor into losing weight. New PT article:


Wednesday, December 02, 2009, 7:32 AM

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Counting calories is importatnt because excessive intake of calories results in obesity. When I don't count calories I eat portions that are double the size I should be eating and I reach for the foods with the higher fat content because I like them more. Counting calories keeps me disciplined in my eating.

Weight X 10 = Calories Per Day
If you want to weigh for example 140 pounds, multiplyl that by 10 which = 1400. That is the number of calories that will support a weight of 140 pounds. If you weigh more than that you will drop down to 140 pounds. If you eat less than 1400 of course you will loose weight faster.

This is a rule of thumb. Once you master it you can tweak it a little for your specific needs.

Another rule of thumb: If you aren't losing weight you aren't cutting back enough on your calories.

Wednesday, December 02, 2009, 9:37 AM

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Out of all the foumulas on the page i must say i think this one is the best. i weigh 244lbs. i have so far lost 20 lbs in a little over a month and felt i was starving myself at 1500 cal a day. i am trying to get to around 175-180 lbs. According to your calculation i can eat about 1800 calories. Simple yet helpful thanks i will start today. But since I work out about 5 days a week does this mean I ned to increase my calorie intake or keep at 1800?

Friday, November 11, 2011, 11:21 AM

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If you're not hungry at 1800 calories and you're losing weight i dont see the need to eat more calories. Remember, you have excess fuel at your disposal!

Friday, November 11, 2011, 2:43 PM

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That formula is way off the mark!
It indicates I should eat 2,700 calories/day!

I eat around 1,500 calories a day and that sustains my weight close to 152 pounds (I'm 5'8") and I work out at the gym on a treadmill for an hour and then use resistance equipment every other day.

Here is a simpler formula...
To figure out how many calories you should eat, take the number of pounds you want to weight and add a zero. That is how many calories you should eat.
For example:
If you want to weigh 130 pounds, eat 1,300 calories per day.
If you want to weigh 147 pounds, eat 1,470 calories per day.

Friday, November 11, 2011, 6:06 PM

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I suspect that there is an error in this original formula having to do with a mathematical operation. If, instead of adding the result of step 3 (age X 4.7) you subtract it, then follow all of the other steps as directed you come up with a much lower number. This seems more intuitive because as we age we tend to slow down a bit and require fewer calories.

Friday, November 11, 2011, 10:01 PM

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