How to Work Out Your Macros for Bulking Without Gaining Fat

You can put on muscle eating any foods you like, provided they fit into a good macronutrient split.
This post will teach you how to calculate a good macronutrient split for yourself that, if followed, will lead to muscle gain with minimal fat gain.
If you need to break through a weight gain plateau, it’s very likely you’re not eating properly for your goal. This post will help you.
Alternatively, if you want to lose fat click here to find out what your macro split for fat loss should be.
Some Pre-requisites for Muscle Gain
There are no muscle building secrets. You just need to nail all of the basic principles.
- You must be strength training, lifting weights (or bodyweight training) with progressive overload on a consistent basis. People say you can make progress with just a 2x weekly routine. This is probably true. However, it’s unlikely to be optimal. I’d say you should be lifting weights a minimum of 3 x weekly with mostly compound exercises.
- Your training NEEDS to be progressive. If you always lift the same weights for the same reps, you’re not demanding your body to adapt to a new stimulus. You won’t gain muscle, regardless of what you eat. How many sets and reps should you do?
- You MUST be in a calorie surplus to gain muscle. The following calculations will estimate what that is for you. It may be off slightly. Everyone is individual. You need to track your weight on the scales and ensure you’re gaining. About half a pound per week is what you want to see.
If you’re a beginner wanting to gain muscle, click here to see a beginner full body workout program.
Don’t Use This Ideology to ONLY Eat Junk
Yes, following flexible dieting or IIFYM (If It Fits Your Macros) allows you to eat pizza, ice cream, chocolate and whatever else.
However, you shouldn’t just fit whatever junk you can into your macros just so you get to eat ALL the “bad” foods. You can’t just eat whatever you want when bulking.
You DO need micronutrients.
Micronutrients are vitamins and minerals. Whilst they don’t contain calories, they are important for your health. If you’re deficient in Vitamin D, your bones are going to be weak. If you’re deficient in Vitamin C, you’re going to get sick. Vitamin A, B6 or B12 deficiencies mean muscle protein synthesis is going to be sub-optimal.
Whilst macros are all that matter for DIRECTLY affecting body composition, micronutrients affect your health, which will affect how you train and how efficiently you can USE those important macronutrients.
What’s the best thing to do? Take a multivitamin AND make sure 80% of your diet is from nutritious food. If you do this, and hold back 20% of your calories for enjoying yourself, you’ll have a great diet that’s easy to stick to.
Don’t worry about the odd day here and there where you hit your macros, but you ate out at an ice cream parlour and it was more than 20% of your calories. Just take an 80:20 view of it. As long as the vast majority of the time you’re not doing things like this, it’s fine.

Something I ate that was definitely more than 20 percent of my calories that day.
OK – with that said, let’s get on to working out your macronutrient split for building muscle!
First Calculation – Calories Required
Tracking the calories you’re eating means you can fit foods you enjoy into your diet and still make progress towards your goals.
Yes, this even means you can eat chocolate, cookies or ice cream and still lose fat, or gain muscle.
You just need to know what your maintenance calories are, and then eat a sensible amount more or less than this number, depending on whether your goal is to gain or lose.
Click the link below to try out my macro calculator which will give you a rough ballpark figure from which to begin tracking, as well as a recommended macro breakdown that is customisable!
This will give you a ballpark figure. It’s not perfect because the options for your activity are quite limited, and we all have very different levels of day to day activity – e.g. office worker vs. another office worker who moves around more vs. a chef or a teacher.
How do I know if these figures are correct?
You’ll have to try eating the amount given to you for a few weeks and see what happens to your weight. If it stays the same, that’s your maintenance!
If you want to build muscle, you should be in a small calorie surplus. Big, untracked surpluses are dreamer bulk territory! This is where you gain a lot of fat, but are convinced the gains are nothing but lean muscle!
Your surplus should only be 10 – 15% above your maintenance calories.
Maintenance estimated at 2,500? Eat 2,750 to 2,875 calories for gaining.
Another way you can get your bulking calories (note I said bulking, not maintenance) is to do the following (very rough) calculation:
Take your bodyweight in pounds and multiply it by:
- 18 – If you have a sedentary job, don’t move around much and you train hard with weights 3 times per week.
- 19
- 20
- 21
- 22 – if you have an active job (e.g. construction worker) and train hard with weights 4+ times per week.
Don’t assume you’ll build muscle faster by picking a higher activity multiplier! Use a low number to begin with. No weight gain? Go with the next number for your activity multiplier. When you’re seeing weight gain between 0.25 and 0.5 pounds per week, you’re good. You don’t really want more than 0.5 pounds per week. There will be more fat gain than you want at that rate. Try to get closer to 0.5 pounds per week if you can.
What Are Macronutrients?
Macronutrients are protein, fat and carbs. You need the first two to survive and to build muscle. You don’t “need” carbs, but in my opinion you’ll do so much better (especially gaining muscle) if you include them in your diet.
All food can be categorised as one of the above, or a mixture of 2, or all 3 of them..
The amount of each that you eat also determines how many calories you eat.
Protein = 4 calories per gram.
Carbohydrates = 4 calories per gram
Fat = 9 calories per gram
Protein
Protein is for building and repairing muscle. It’s incredibly important you get enough protein when you want to gain muscle, as it’s the building blocks that the new muscle will be made from.
Protein is more satiating (fills you up) than other macronutrients and requires more calories to digest (thermic effect of food) so it’s a good idea to consume more of it when in a fat loss phase. OVER consumption of protein when trying to gain weight is therefore not recommended. It doesn’t provide any more muscle building benefit past a certain point, will fill you up to much (preventing you from getting into a surplus) and cause you to burn more calories digesting it (also preventing a surplus).
Fat and Carbs
Fat in the diet is used to absorb vitamins, and is essential for proper hormone function. This is why you MUST eat fat.
Carbs are your body’s preferred source of energy. They will allow you to have great workouts and also provide energy for processes like building muscle! They are not evil, nor do they make you fat. Even eating carbs at night will not make you fat!
Carbs WILL make you fat if you consume enough of them to go way over your maintenance, but then the same can be said for fat or protein.
So, how should you split up your calories between the different macronutrients?
How to work out the optimal macro split
Take your bodyweight in pounds. Unless you’re overweight (and if you are, you should be reading this blog post instead), that’s how much protein you should eat. There’s no need to go higher than 1 gram of protein per pound. For example, a 180lb man would eat between 144 and 180 grams of protein. The actual figure we want is 0.8 grams of protein per pound of LEAN body mass. For most people looking to gain muscle, 1 gram per pound of TOTAL body mass will get them in the right ballpark or slightly above (which is no problem, a little extra to make sure doesn’t hurt!)
Now take your bodyweight in pounds again, and multiply it by 0.4 – 0.6. This is how much fat you will eat. The reason for this range is that there’s a MINIMUM amount of fat you should eat, but not really a maximum. Whatever we choose here will affect how many calories are left over for carbs. If you really like carbs, choose a lower number. If you like bacon, sausages, eggs, avocados, nuts etc. choose a higher number here. Example 180lb man would eat between 54 and 108 grams of fat.
We now calculate the calories eaten from fat and protein, and subtract this combined total from the total calories we already defined to get the calories we should eat from carbs.
An Example Macro Split
180 pound male. Estimated bulking calories of 2,875.
Protein = 180g. Protein = 4 calories per gram. Calories from protein = 720.
Fat = 90g. Fat = 9 calories per gram. Calories from fat = 810.
Combined calories from fat and protein = 1,530.
Calories from carbs = Total calories for bulking (2875) MINUS calories from fat and protein (1,530) = 1345 calories.
Carbs = 4 calories per gram. 1,345 calories / 4 = 336.25 grams of carbs (call this 335 for simplicity).
You can move calories between fats and carbs from day to day if you like. You don’t have to rigidly stick to whatever split you work out. As long as you hit protein, get in nutritious food, and hit your total calories, then it’s fine. Some people find they perform better if they keep their carbs around their workouts and eat fairly low carb the rest of the time. If this is you, you’ll want to use a higher number like 0.6 x Bodyweight for fat, so you have fewer carbs to cram in around your workouts or late at night.
Remember, the objective is not to fit as much crap as possible into our diets.
The objective is to allow ourselves to have ice cream sometimes, or to borrow macros and calories from one day and pay them back on the next. This allows our fitness goals and our lives to fit together more easily.
Diet is only one part of the muscle building equation.
Of course, there are a myriad of other things you need to get right. Check out Simply Build Muscle to see what else you need to apply to your program in order to get serious muscle building results.