My goal is to gain weight, primarily for muscle bodybuilding (not professional). In various online calorie calculators I need to choose my activity level. I'm always stuck on which one to choose.

For example, this one (http://www.calculator.net/calorie-calculator.html), along with many others, has a drop-down for activity level, usually containing levels between sedentary and very active.

My workout is 3x a week weightlifting, 3 sets of 8-12 reps, 3 day split, in the gym about 30-45 mins. Am I supposed to include my workout activity into this calculator?

But my job is largely sedentary, sitting on an office chair. My home activity is fairly sedentary.

What should I pick to get a better estimate of calories for weight gain?

4 Answers 4


A warning at the beginning: Calorie Calculation is inaccurate, these calculators only give a rough estimate at best.

What to chose depends on what you want to do with the results and if you are planing to count calories for your exercise separately.

If you don't want to track your activity, select the light or moderate activity and use that number as a first estimate, read below how to adjust the number to make it more accurate.

If you want to do so, you should calculate your BMR or the sedentary level and add activities on top (optimal would be to calculate the RMR - Resting Metabolic Rate). You need to be careful doing this, as a lot of calorie calculators for different activities already include your RMR. You can check this by calculating the caloric burn for a sedentary activity, like watching TV, reading a book or sleeping. If the number is higher than a few calories, they add RMR. In this case you have to subtract that number from the calories of an activity.


Caloric Burn:
2000kcal/day ~ 83kcal/hour

Watching TV / hour (according to calculator):

Riding bike / hour (according to calculator):

Riding bike / hour (without sedentary rate):
(240-85)kcal ~155kcal

Daily Caloric Burn for sedentary activity plus an hour of biking:
2155kcal instead of 2240kcal

Calories are a useful tool to measure how much you eat, and are especially useful as they probably have a psychological effect and make yourself more aware about the stuff you eat, but they are, as said before, inaccurate.
Don't solely rely on them, track your weight with a scale (don't get distracted too much by fluctuations though), measure your body fat (with a skin fold caliper for example) and take photos of yourself to compare.
You can use all the combined measurements to get a better estimate of the number of calories your body needs.

  • 2
    I might dispute the highly inaccurate a bit, but they are estimates. When I track it, I calculate my BMR by two or three different equations, and then add all my activity in on top of that.
    – JohnP
    Aug 23, 2013 at 14:29
  • @JohnP I think we simply have different expectations, removed the highly anyway. Using different equations helps, I'd always prefer to use one instead of a calculator, as that's more transparent. However I am only counting calories every once in a while, as it can get annoying to accurately track everything. And a simple visit to the canteen skews the whole calculation.
    – Baarn
    Aug 23, 2013 at 22:20
  • Agreed. One bad night can erase an entire good week :(
    – JohnP
    Aug 23, 2013 at 22:38

Before using the weight loss calculator I recommend you the best calorie calculator to accurate estimate of your daily calories required for loss.


Using Calorie Counters for the lifter/athlete/in-training

  1. If you want a pretty accurate calorie count you need to use a calculator that is not just height/weight/age based. It needs to be height (helps estimate skeletal, organ, and fluid weight), weight (for ratios), and body fat % (so that you can get some kind of estimate for muscle weight). You don't have to get your body fat % every day but you need to check it during intervals to update your counter.

  2. Your muscular weight is going to have a huge impact on the amount of calories you burn per day. Without knowing it the calorie counter is trivial for the athlete or lifter. Most calorie counters either assume a body fat % or they assume that anything over a certain weight for a given height can be attributed to fat (based on gender).

  3. When using the counter the calories burnt per workout is very very hard to estimate for lifting weights. There are some decent estimates for basic things like running, walking, activities. These are guesses usually based on your weight. They are OK to use. They could be off by as much as 10-30% though for in-workout calorie burn. For someone 160-180 pounds lifting for 45 mins I would give at least 200 calories. Why not 250 for you since you are looking to gain weight.

  4. The afterburn is the real deal. The more intense your workout the more calories your body will burn after your workout (while your body is still cooking) and during recovery. There are studies that bicyclists have burned up to 700 calories AFTER a ride - THE SAME DAY. Didn't even take into account the full recovery process. If you are trying to lose weight, then you can just ignore this afterburn - you will just lose weight quicker. But if you are trying to gain weight you are going to have to really use your best judgement. If your weight workout is at a very high intensity for 45 mins I could see adding anywhere from 400-1000 calories based on your weight/muscle mass. But here is the deal. This isn't a one time one day addition. When I work with one of my athletes and dieticians we normally attribute 60% of the after-burn calories to the workout day and spread the rest through out the week (done so that you fuel your body properly for recovery periods). You work out 3 days. So let's say you calculate your total per workout afterburn to be 600 calories - pretty intense. So you would gain at least 360 calories on the 3 workout days. And then 240x3=720 divided by 7 days = 103 extra calories per day. So a total of an extra 463 calories on workout days and 103 on non-workout days. Simple but easy. You can spread the calories a little more if you want balance but you have to account for them (and you should be eating/drinking more calories on workout days).

  5. If you are sedentary at a desk most of the day then pick a very low activity level. But if you go for a walk or anything on a regular basis you need to add it in so that it is accurate. Walking to the store everyday might seem like normal life but it might be 100 calories a day which adds up (maybe with 1 calorie afterburn too).

  • Do you know how or if afterburn is accounted for in calorie calculators for certain activities, or do you add up some number on top of the caloric burn for a given activity?
    – Baarn
    Aug 23, 2013 at 22:09
  • The 700 calories cyclist burned after a ride is a bit useless without knowing how much they burnt during the ride, it would be nice if you could add the corresponding numbers to put that in perspective.
    – Baarn
    Aug 23, 2013 at 22:11
  • I would be interested in the study that you cite - The published studies that I've seen suggest that the "afterburn" effect is around 100 calories (A couple studies go higher, but require extended exercise periods). Edited - I'd be interested in seeing the source for any of your references.
    – JohnP
    Aug 23, 2013 at 22:48
  • 1
    @Informaficker - As far as I know, the calorie estimates for activity that I've seen ignore EPOC (Excess Postexercise Oxygen Consumption) effects, as it is usually in the range of 30-100 calories depending on type/length of activity.
    – JohnP
    Aug 23, 2013 at 22:53
  • No calorie counter I have seen account for afterburn. Here is a article I found googling. I think it references the same study I read about 6 months ago - nytimes.com/2011/04/19/health/nutrition/19best.html?_r=1&. Over the past few years there have been quite a few studies around that and it really points to intensity - not total calories burnt. Probably why I have seen a lot of short distance track athletes stay skinny/fit while really not putting that much time into their activity (and eating whatever they want).
    – DMoore
    Aug 24, 2013 at 3:18

Here I am showing you how I do it and I know the question is only about which activity multiplier to use but it seemed easier to do it this way.

Note about Body fat: You will need to get this one as close to the actual value you have as this will all be based off that.

I am using the Katch-McArdle formula. Different websites refer to the value you get as either RMR (Resting Metabolic Rate) or BMR (Basal Metabolic Rate) but it is the same thing.

My weight: 72.2Kg Body fat: 10%

Formula Lean Body Mass: (Weight x (100-(Body Fat)))/100

((72.2 x (100-10))/100 = 64.98

Formula: BMR = 370 + (21.6 x Lean Body Mass(kg))

370 + (21.6 x 64.98) = 1773.57

This mean that if I were to never get out of bed, not even to go to the bathroom simply being alive will cost me 1773.57 calories per day. In order for this to be correct I will now add a value for activity multiplier which is simply a way to add calories for you moving around, working, and going to the gym. I am adding 1.55 which means I am moderately active. This value is called total daily energy expenditure (TDEE) and for me this is 1773.57 x 1.55 = 2749.0304.

You will notice that a lot of sites will tell you to start with about +500 calories over maintenance mode (This is 99% of the time to much) but I started at maintenance mode itself and added 50 calories/week until I found my perfect value.

Activity Multiplier

A paper on metabolism used a definition of "vigorous exercise" as expenditure of 14.1 to 16.3 kcal/kg of ideal body weight per day.1 Using the rounded figure of 15 Calories per kilogram of body weight, then "vigorous exercise" for a person weighing 150 pounds (68 kilograms) corresponds to 1020 Calories per day. If walking at 4 miles per hour burns about 300 Calories per hour, then you would need to walk 3 hours and 24 minutes to burn off 1020 Calories.

The activity factors for the Calorie Restriction Calculator are:

1.200 = sedentary (little or no exercise) 1.375 = lightly active (light exercise/sports 1-3 days/week, approx. 590 Cal/day) 1.550 = moderately active (moderate exercise/sports 3-5 days/week, approx. 870 Cal/day) 1.725 = very active (hard exercise/sports 6-7 days a week, approx. 1150 Cal/day) 1.900 = extra active (very hard exercise/sports and physical job, approx. 1580 Cal/day)

The activity factor lightly active corresponds to walking 2 hours per day, moderately active corresponds to walking 3 hours per day, very active corresponds to walking 4 hours per day, and extra active corresponds to walking 5 hours per day (20 miles). More strenuous exercises, such as climbing stairs or running, burn more calories per hour. Most people who exercise from 30 minutes to 45 minutes per day are in the "lightly active" category. You can use the CR calculator to determine the number of calories for each level of exercise for your particular weight by subtracting the calories for a specific activity level from the calories for the sedentary option.

Nutritional regulation of the insulin-like growth factors.
What is moderate exercise?

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