How accurate is the MFP BMR Calculator?

Larassa
Larassa Posts: 3 Member
in Getting Started
So I'm 5 feet 5 inches, age 19, female, and last time I weighed myself (back in January because I don't have scales at home) I was 123 pounds. The BMR calculator on here says my BMR is 1,338 calories a day. Does that seem right because to me that's looks pretty low, and I don't want to eat too little and starve myself! However, I do put on weight very easily, and that might make sense if the reason is that my BMR is very low. What do you guys think?

Replies

  • mrsdouglas2014
    mrsdouglas2014 Posts: 3
    With fat secret mine was 200 cals higher. I still lost weight. I'm 5"4 age 30 my recommended calories here is about 1500. I think you may have set your amount exercise too low
  • mrsdouglas2014
    mrsdouglas2014 Posts: 3
    Have a look at the settings in your diet profile. Maybe set your weightloss goal at 1lb a week and check the exercise? Hth
  • NerdySamoan
    NerdySamoan Posts: 78
    BMR is your Basal metabolic Rate.
    Basically if you were to sleep for an entire 24hours , you would still burn 1338 Cals just for being alive. (basically its the calories your body burns to keep your organs, brain and breathing functioning)

    Its your TDEE (Total Daily Energy Expenditure) that you want to find. This is you BMR + ACTIVITY LEVEL.

    Eating you TDEE is maintaining weight
    Eating 20% below your TDEE to lose weight.
    Eating 30% above TDEE to gain weight.

    i would guess if your BMR is 1300 then your TDEE would probably be around 1900 in which case you would want to eat around 1550cals.

    DONT eat too close too your BMR. This means youre eating just enough for your body to function and it will start to look at other ways to save itself, easiest being to slow your metabolism down so you dont lose fat and then it will start eating muscle'for energy.

    Heres a link to find your TDEE, if you know you BF% then its alot more accurate
    http://iifym.com/iifym-calculator/

    hope it helps
  • neandermagnon
    neandermagnon Posts: 7,436 Member
    MFP told me I should eat 1500 for maintenance

    I actually maintain at around 2100 cals/day and 1800 cals/day is a slow cut. 1500 cals/day is not even a sustainable deficit for me.

    Thing is, calculators, any of them, not just the MFP one, are based on averages. I have a high lean body mass for my height, that probably makes a difference. Katch McArdle (which is based on body fat percentage so takes lean mass into account) gives a much closer number, although it's not spot on.

    Calculators should be used as a starting point, i.e. start with the number the calculator gives you, try it for a couple of weeks, make sure you're logging accurately and then adjust the number of calories based on what happens, i.e. if you're not losing then subtract a couple of hundred calories and try again.... if you're starving hungry all the time, add 100 calories and see if that helps... if you're losing too fast then add 100-200 calories and try again.... etc until you find your ideal number of calories... it needs to be a number where you're getting enough to eat, don't feel deprived (i.e. you have room to include a bit of all the foods you want to eat, even if the portion sizes are small) yet you're still losing weight.
  • Larassa
    Larassa Posts: 3 Member
    Ahh thank you that makes a lot more sense now! Using that link, it says my TDEE is 1800, and the suggested calories a day for fat loss is 1470 if I exercise 3 times a week. I've set my goal at 1400 net per day so that seems about right. But I don't want to screw up my metabolism so I wont go below that.
    The amount of exercise I do varies quite a lot though; sometimes I do about 8 hours of cardio a week, sometimes a lot less, so would it be wise to change my calorie goal daily/weekly depending on how much I am doing?
  • NerdySamoan
    NerdySamoan Posts: 78
    yeah your TDEE will change with your training days.
    But once you have a general idea of how much you burn on what days you can eat accordingly.
    Good luck
  • Larassa
    Larassa Posts: 3 Member
    Great, thanks a lot everyone :) I guess I'll just have to do a bit of experimenting...
  • ncfitbit
    ncfitbit Posts: 1,058 Member
    NerdySamoan wrote: »
    BMR is your Basal metabolic Rate.
    Basically if you were to sleep for an entire 24hours , you would still burn 1338 Cals just for being alive. (basically its the calories your body burns to keep your organs, brain and breathing functioning)

    Its your TDEE (Total Daily Energy Expenditure) that you want to find. This is you BMR + ACTIVITY LEVEL.

    Eating you TDEE is maintaining weight
    Eating 20% below your TDEE to lose weight.
    Eating 30% above TDEE to gain weight.

    i would guess if your BMR is 1300 then your TDEE would probably be around 1900 in which case you would want to eat around 1550cals.

    DONT eat too close too your BMR. This means youre eating just enough for your body to function and it will start to look at other ways to save itself, easiest being to slow your metabolism down so you dont lose fat and then it will start eating muscle'for energy.

    Heres a link to find your TDEE, if you know you BF% then its alot more accurate
    http://iifym.com/iifym-calculator/

    hope it helps

    I know this is an old thread, but thank you! This is the clearest explanation I have found. :)

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