Advanced Macro Calculator and How to Use It for IIFYM

Enter your details in the macro calculator below to get customised macronutrients, including your estimated TDEE, how much protein to eat, and how many carbs and fats.

There are different options depending on your preferences for protein intake and carb/fat split.

Please read the instructions below the calculator! This will help you to get the best possible results for fat loss or gaining muscle.

Macro Calculator




What Are Macros?

Macros is a shortened term for macronutrients.

Macronutrients are the main food groups that make up all foods.

They are Protein, Fat and Carbohydrate.

Some foods are made up of mostly just one macronutrient, others are a mixture of two or three to varying degrees.

Macronutrients contain calories. Protein contains 4 calories per gram, fat contains 9 calories per gram and carbohydrates contain 4 calories per gram.

There is a 4th macronutrient, alcohol, that contains 7 calories per gram.

There are also micronutrients. These should not be confused with macronutrients. Macronutrients are required in large amounts by the body. Micronutrients are also required, but only in small amounts. There are also many more than just 4 micronutrients. Micronutrients do not contain calories, but macronutrients do.

Examples of micronutrients are things like calcium, vitamin c, B12, iron, folate, magnesium, vitamin d, etc.

Macro Calculator Instructions and FAQ

Track your macros accurately with a food tracking app such as MyFitnessPal and stay on track with your workouts to achieve your body composition goal!

You need to be accurate with your food tracking! If you’re not accurate, you’re not really following your macros because you can’t be sure of the quantities you’re actually taking in. Weigh foods with a digital scale as much as possible, until you get a practised hand/eye.

This is a starting point

Chances are, this isn’t going to get your ACTUAL exact TDEE (total daily energy expenditure). After all, we’re not all split into groups of people who can be categorised by “sedentary”, “lightly active” and so on. You may work out 3 times a week and spend most of the rest of your time sitting. Someone else who works out 3 times per week might spend twice as long in the gym and then work all day making deliveries. Obviously you’ll burn different amounts of calories.

This is a “best guess” to get you in the right ballpark. Once you’ve been tracking for a couple of weeks, weigh yourself and see what’s going on. If you’re not getting the desired results then you need to adjust your overall calories.

The best way to weigh yourself and analyse your progress is to weigh yourself daily under the same conditions, then compare weekly averages of your weigh-ins to make a judgement about what’s happening. Weigh yourself first thing in the morning, with no clothes on, after using the toilet, and before eating or drinking anything.

I don’t know my body fat percentage!

Compare yourself to these pictures and take your best guess:

bodyfat percentage examples


For a more detailed explanation of how to estimate your body fat percentage, see this post.

I don’t know what to put for protein preference!

It’s kind of up to you. Anything will work (unless you’re overweight/obese – read instructions below). 1g of protein per lb of your bodyweight is the standard, however a lot of science does not support that intakes this high are necessary. It’s just easy. Weigh 160 lbs? Eat 160g protein.

This study analysed 49 other studies with 1,863 total participants and found significant evidence that 1.6g of protein per kilogram of bodyweight was the maximum that was needed. Beyond this there was no further benefit for hypertrophy. This is about 0.73g per lb.

However, it should be pointed out that lean mass is probably what really matters, not total body mass. Protein is used to repair muscle tissue. Having a lot of extra fat mass around shouldn’t really affect how much protein you need to maintain muscle, or build new muscle.

Therefore there are options in this calculator to base protein intake off of lean mass. If you choose one of these, then your entry for body fat percentage needs to be somewhat accurate. Don’t know your body fat percentage? Use this guide to help.

I weigh 300 lbs (or whatever), do I really need to eat 300g (or whatever amount) of protein?

No, definitely not.

If you’re overweight/obese, don’t use standard (1g per lb) for protein. Base your protein intake on your lean mass (choose 1g or 0.82g per lb of lean mass). Make sure your body fat percentage entry is accurate, as your protein target will be based off of this.

If you still have no idea, then you’ll have to enter 1g per lb (standard) and then adjust your results slightly. Change protein to your goal weight in lbs. Goal weight 180lbs? Eat 180g of protein. Then take whatever you subtracted from protein and add it to carbs.

Example: Calculator gave Protein: 315, Fat: 167, Carbs: 66. Goal weight is 180 lbs. Set protein at 180g and add the difference to carbs. Difference is 135. New macros = Protein 180, Fat: 167, Carbs: 201.

Important! Do not add the grams you subtracted from protein to fat, only add them to carbs. This is because Protein and Carbs are both 4 calories per gram. Fat is not, it is 9 calories per gram. Adding them to fat will increase your total calories quite significantly. If your carb goal goes too high after adding protein, then try using a different carb preference (low or zero).

What should I put for carb preference?

This is totally up to you. It doesn’t really matter.

Most people do better eating at least some carbs, and low carb intakes can cause them to feel quite grouchy and/or tired. If you choose low or zero carb, make sure you know what you’re letting yourself in for. Some people thrive on it, and there is anecdotal evidence that it clears up some issues relating to skin and digestion. If you have no problems eating carbs, you’ll probably want to go for moderate carb intake at least.

Can I really eat ANYTHING and lose weight/gain muscle as long as it fits these numbers?

Well, kind of. Firstly, it’s not going to work if your tracking is totally wrong so you’re not actually following the numbers. Nor will it work if you’re not working to the right numbers to begin with (overestimating your activity level or underestimating your body fat percentage).

You also shouldn’t use this as an excuse to just hit your protein number by drinking 8 scoops of whey protein per day, then fill up carbs and fats with ice cream and cake.

Whilst technically that will work for body composition, it won’t work long term because of the impact on health.

You’ll be deficient in key nutrients because so much of the food you’ll be eating will be “empty calories” containing no nutritional value.

It’s important to hit your intake of various micronutrients (e.g. iron, zinc, magnesium, B12, Vitamin A, C, E, K, etc.). If you don’t you’ll run into all kinds of health issues. Your body won’t function properly to optimally recover from training. You’ll get sick and be unable to train. You won’t be able to properly use the macronutrients you’re taking in. What good is 1g of protein per lb of your bodyweight if you lack B12 and folate that’s required to turn it into muscle tissue?

So whilst using macro targets allows you a lot of flexibility in your diet, it shouldn’t be used as a way to only eat junk. A good rule to follow is to make sure that a minimum of 80% of your calories comes from nutritious, whole food sources. The other 20% can be from “fun” foods. This could be 80:20 every day, or you could be closer to 90-100% most of the time, and then use greater amounts of flexibility for entire days.

How do I fit alcohol into my macros with this calculator?

calculating alcohol allowance with macro calculator

I’m yet to come across a calculator that gives you an alcohol recommendation. That’s because alcohol is generally not recommended! People get into lifting and nutrition for health, right? And alcohol isn’t optimal for health.

BUT, you’re a responsible adult, and alcohol can certainly be enjoyed infrequently and in moderation without ruining your health or your progress.

If you want to know how to fit alcohol into your macros, just track it as carbs and take it from your carb allowance.

Focus on hitting your protein goal first. Once you’ve got this out of the way, you can fill your macros with whatever else and it won’t matter massively for body composition.

Say you’re going out for a few drinks, and you want to fit them into your macros. Just convert however many macros you’ve got left back into calories.

You’ve hit protein, but you’ve got 20g of fat and 100g of carbs left in your macros.

I would advise hitting the fat macro as well as protein, because there is a minimum amount of fat your body needs for proper function. This is more important if your goal is fat loss, as your fat and carb numbers will be lower, and fat will be closer to or at the minimum. If you hit your fat macro from nutrition food, then there will just be 100g of carbs left that you can shunt over to alcohol.

Just convert your carb grams to calories by multiplying by 4.

In this example that means there’s 400 calories left for carbs. This will give room for about 3 bottle of beer (providing they’re normal sized). Always check how many calories are in your drink so you don’t accidentally go over.

The true test will be to see if you can stick to your macros once you’re 3 beers in!

Macros are part, not all, of the battle

Changing what you eat goes a long way towards changing your body composition. You can lose fat just by changing what, and how much, you eat.

Any exercise will help the process as it will increase the amount of energy you expend in a day (TDEE), improving your chances of being in a calorie deficit (required for fat loss).

If your goal involves gaining muscle (and I recommend it does, for health and quality of life reasons) then this will not happen unless you are resistance training.

You can gain strength and muscle with light weights. Any routine should be challenging, incorporate progressive overload, and also allow for adequate recovery.

I recommend any routine you follow prioritises compound exercises.

Here’s a good beginner routine you can follow, and a good routine for intermediate to advanced trainees.

Need more help?

If you’re one of my clients I’ll do this for you, suggest where I think the macros might need tweaking, and help you with finding foods that allow you to hit these numbers.

That’s in addition to me building your custom workout program, being on hand via direct messages to help you and answer questions, help you set and achieve goals and keep you accountable.

Sound good? Read more here and apply.