The cornerstone of any good fitness plan is getting your diet right, and to do that, the first thing you need to do is to determine what your daily calorie needs are.
There are a lot of different online calculators you can use to find out how many calories you should eat per day. Some of them are ok, but most calorie calculators oversimplify by only using your age, weight, and gender (and perhaps BMI).
If you are a fitness nerd like me, you will probably want to know the correct scientific way of calculating what your daily calorie needs are.
It’s a very easy 5-step process. I have used my own data in the example below to show you how I work out what my daily calorie needs are.
How to calculate your daily calorie needs
You can calculate your daily “maintenance calories” by following these easy steps:
Step 1: Find your current body weight in kilograms (if you live in the US, just divide your current weight in pounds by 2.2 to get your weight in kilograms).
Step 2: Multiply your weight in kilograms by 0.9 if you are a woman or 1.0 if you are a man.
Step 3: Multiply by 24
Step 4: Multiply by your “Lean Factor” from the table below (read on to learn how to find your body fat percentage if you don’t know it)
Example using my stats: 61 kg (134.5 lbs.) x 0.9 (female) x 24 x 0.95 (20% body fat) = 1252
This number is called your Basal Metabolic Rate (BMR). It’s how many calories you would burn in a day if you just lay on the couch all day and did nothing.
To find out how many calories you actually burn in a day, you need to multiply with your “Activity Modifier” from the table below.
Step 5: Multiply by Activity Modifier
My daily calorie need would be: 1252 (my BMR) x 1.55 (Light Activity) = 1940 calories/day
Important: No matter what this formula says, never eat less than 1,200 calories per day on average without consulting your medical team first. A very low daily calorie intake can lead to a slower metabolism, hormonal problems, and a number of other medical issues.
How to find your body fat percentage
As you can see, calculating your daily calorie needs is actually pretty simple, as long as you know your body fat percentage. Most gyms should be able to measure that for you, or a trainer can give you a very good estimate just by looking.
You can also use a tape measure and this online calculator to estimate your body fat percentage. It’s not as accurate, but you really only need an approximate number, so it should be good enough.
If you want a more accurate number (and to track any changes), you can invest in a scale that measures body fat percentage (you can buy the one I use HERE). It’s only $27.99 so it’s a worthwhile investment if you want to track your weight and body fat percentage.
How to decide your activity factor
The main mistake people make when using this calculation is to overestimate their physical activity level.
Even though I live a very active lifestyle and work out almost every day, I still only use the “Light Activity” multiplier. And that may even be on the high side because I also spend a lot (too much) time in front of a computer.
The higher multipliers are for people who use their bodies almost constantly throughout the day and therefore need a lot of energy, like construction workers, pro athletes, etc.
If you are pretty fit and active, you should probably use the “Light” or “Very Light” multiplier. If you are just starting a fitness program, use the “Very Light” multiplier.
Now that you know how many calories you burn in a day, the next step is to decide if you want to lose or gain weight.
How many calories should you eat to lose weight?
If you are trying to lose weight, I recommend eating around 400-500 calories less than you burn daily. That calorie deficit should lead to a weight loss of about 1 pound per week, which is a very healthy and sustainable weight loss.
I know it can be tempting to lower your daily calorie intake more if you are trying to lose weight, but it’s not a good idea. When you lose weight quickly by restricting your calories, you also lose muscle mass, and the weight you lose is much more likely to come right back (as fat) as soon as you stop dieting.
Instead, add more physical activity to your daily routine. Even just 15-30 minutes of light to moderate exercise such as walking can burn calories, increase your metabolism, and help you reach your goal weight.
To learn more about healthy calorie deficits, read our guide Can Eating Too Little Make You Gain Weight?
How many calories should you eat to gain weight (muscle)?
If you want to gain muscle, start out at 500 calories/day more than your maintenance calories and see what happens. If you find that you are also putting on a little too much fat, decrease your calories slightly.
Just like weight loss, healthy weight gain should happen slowly. If you want to gain weight and add muscle mass without adding (much) fat, focus on eating a healthy diet, incorporate exercise (and especially resistance training) into your daily routine, and aim for a caloric intake that’s only slightly higher than your maintenance calories.
How accurate is this formula?
While this calorie calculator is quite accurate for most people, it is based on an “average” person and therefore isn’t perfect for everyone.
It doesn’t take differences in natural metabolism into account, so if you have a particularly high or low metabolism (for example because of thyroid disease), the result from this formula won’t be accurate.
Because your natural metabolism declines as you age, the formula also tends to underestimate how many calories teenagers need and overestimate the daily calorie requirements for people older than 60.
It’s also the most accurate for people who are close to the “average weight”. If the result of your calculation is that you need less than 1,400 daily calories or more than 2,500 daily calories to maintain your current weight, then it’s recommended that you talk to your doctor or dietitian before making any changes to your diet.
Frequently asked questions
There are roughly 3,500 calories in 1 pound of body fat. This means that, in principle, you will lose 1 pound per week with a calorie deficit of 500 calories/day (3,500 calories/week).
In reality, weight reduction is often a little slower than this as your body adjusts dynamically to any calorie reductions by lowering your metabolism.
It can be very hard to know how much you are actually eating without counting calories. Research shows that people eating in fast-food restaurants underestimate how many calories are in their meal by up to 500 calories.
You can use apps such as MyFitnessPal or Lifesum to track your daily calorie intake (and daily activity).
To ensure you reach your daily calorie targets, it’s also a good idea to follow a meal plan. You can either create your own or simply pick one from my meal plan library.
Atul singh
Mam my height is 163 cm and weight is 50 kg i want gain 1 kg weight per week how it possible and what will be diet plan
Christel Oerum
You’ll need to be in a calorie surplus. You could track what you’re eating now for a few weeks and if that amount doesn’t lead to weight gain add 200-500 calories per day
hala
Hello, Thank you for this article
but I wonder what is the scientific reference of this formula ? because it differs from the Match-McArdle and Cunningham formulas that use the Lean body mass in their equations.
Thank you !
Christel Oerum
Hi Hala, this is the method used by the International Sports Science Association. There are other ways to calculate daily calorie needs, but we think this is the most accurate method that’s still relatively easy to do yourself.
AIZ
Thanks Mam
AIZ
Hello Mam:
My BMR is 1728×1.3= 2246. Mam I have started Gym religiously 6 days a week from 1st oct 2019.
Now I want to reduce my weight almost 8 kg also need muscles so kindly guide me what to do?
weight 80Kg
Height 173Cm
Christel Oerum
The article should guide you to your calorie needs. I’d suggest you start with a small calorie deficit and go from there. Too much of a deficit and too much cardio and you run the risk of losing muscle
Himaz Javed
Hello Mam, my bmr is 1608 and maintainance calories is 2053, I want to lose fat so how much calories should I consume to burn fat
Christel Oerum
Less than 2000. I wouldn’t go too extreme but maybe just a 200-500 calories deficit
Alishia Youngblood
Thank you for this info. I’m currently taking care of an 89 year old man who’d activities each day are pretty much consisting of naps and must handle errands. He doesn’t have diabetes but, is on meds to help prevent his prostate cancer from taking over. The meds he is on make tasting or smelling his food impossible so eating has no joy or importance to him anymore. I have now resorted to blending up all his meals to a pureed type consistency so he ccx will eat something to help keep his from wasting away. I also give his supplemental Boost drinks 3-4 times a day to keep up his calorie intake. I realize that these supplemental drinks aren’t any substitute for real food for him but, it’s like pulling teeth to get him to eat or drink anything. I’m at the end of my rope to where I’ve considered calling him a Nutritionist to help me with this problem. I found your article most helpful as to where his calorie intake should be in a general area to where I can try to keep him sustained at the strength he currently has today.
Heide
I have type one and was a personal trainer. My issue is to lose 25-30 pounds and not go hypo all the time. I take in 200-300 caliries getting my BG back up or to stay ip while trying to lose weight. I try not to over correct and seem to get no where all while calorie counting, walking, and lifting weights. Any suggestions?
I gained 30 pounds years ago after being Dx and constantly being hypoglycemic and eating snacks to raise BG!!
Thanks
Christel Oerum
It sounds like you need to find your formula for exercise and diabetes (read more HERE or consider my ebook). Too much insulin on board (IOB) is the reason you’re going low. So, to reduce the number of lows you have to adjust your insulin. Exercise without constant lows is possible, but it will most likely require a little work to find your formula
Susan
I did this with all the numbers provided by my doctor. Just diagnosed with Type 2. I am freaking out because it totals 2338 calories which seems so high. I have been using an app and it has be at 1230 calories a day and I am always feeling sick to my stomach and being hungry, but I have been good staying away from the carbs.
So is this right?
92.53×0.9x24x0.90=1798
1798×1.3=2338
I’m sure your quite busy but I though I would ask anyway. I don’t need to gain any weight.
Christel Oerum
Remember this is a general calculator. It doesn’t know you or your genetics, so it’s only a starting point. As for your app, being a little hungry is not unacceptable but it sounds like you’re more than that.
So, what I would recommend is to track your calories for 2-4 weeks, maybe stick with something in between the two suggested calorie levels, and see what happens. If you lose weight, great, if not then reduce your calories by 200-300 calories per day and try that out for 2-4 weeks. Remember this will take time, and any progress is progress.
Lana
I’m ready to start Keto. I love this menu because its fairly simple and I know if I get messing around with crazy recipes, I will become overwhelmed and quit. I don’t eat pork and/or most seafood and that seems to be tripping me up a lot when it comes to simple keto meal plans. Is there a good substitute for bacon/bacon bits that has enough fat?
Christel Oerum
You could try adding in avocado or nuts but will depend on the recipe of course
Alok bharali
Hello.. I am Aalok ..I just want to know that how to make a diet list for fat Lose,weight gain and for maintenance..how to give a diet list to a person if he or she want to gain weight and lose fat ..how to make that list proper calorie how can I calculate ..I gt some difficulty in the above calculation…so can u help me out ..
Christel Oerum
If you have a hard time with the calculation you can try and use one of the online calculator (google “calorie calculator”). And remember the calculators are just a starting point. Then reduce or add calories depending on the goal.
An alternative method is to track all calories (liquid as well) for 1-2 weeks and make changes from there. Let’s say you track everything for 2 weeks and see that you’re consuming 2500 calories a day on average. If you’re not gaining or losing weight while consuming 2500 calories, that would be your maintenance caloric level. Depending on the goal you could then reduce or increase the 2500 calories with a few hundred calories.
I hope this helps