If you've ever felt lost trying to figure out how much you should actually be eating, you're not alone.
"Calories" and "macros" get thrown around constantly, but very few people explain how to work them out in a way that's grounded, simple, and actually tied to changing how your body looks and performs.
This guide walks you through it step by step… no jargon, no extreme dieting, just the numbers that matter for building muscle, losing fat, or recomposing your body.
First, what is body composition?
Body composition is the ratio of muscle to fat on your frame… not just what you weigh. Two people can weigh exactly the same and look completely different. One might be lean and strong, the other softer and undermuscled. The scale can't tell those two apart, which is why chasing a number on it is one of the most common mistakes people make.
When we talk about changing your body composition, we usually mean one of three goals:
Fat loss — reducing body fat while holding onto muscle
Muscle gain — building lean tissue, usually with a small amount of fat
Recomposition — losing fat and building muscle at the same time (very achievable for people newer to structured training)
Your calorie and macro targets shift depending on which of these you're chasing.
Step 1: Work out your maintenance calories
This will be your TDEE (Total Daily Energy Expenditure).
Maintenance is the number of calories that keeps your weight stable… you're neither gaining nor losing. Everything else is built off this figure.
Your maintenance calories are driven by a few things: your body size, how much muscle you carry, your activity level, and your daily movement. A rough starting estimate for most people is bodyweight in kilograms multiplied by 30 to 33. So someone at 80kg lands somewhere around 2,400–2,640 calories per day as a starting point.
This is an estimate, not gospel. The real number reveals itself once you start tracking and watching how your body responds over two to three weeks.
Step 2: Adjust for your goal
Once you have a maintenance figure, you nudge it based on what you're trying to do:
Fat loss: subtract roughly 15–20% from maintenance. This creates a deficit that's aggressive enough to see progress but sustainable enough that you don't crash, lose muscle, or rebound.
Muscle gain: add roughly 5–10% above maintenance. A small surplus supports muscle growth without piling on unnecessary fat.
Recomposition: sit at or very slightly below maintenance, and let high protein and proper training do the heavy lifting.
Step 3: Set your protein
Protein is the single most important macro for body composition. It preserves muscle when you're in a deficit, builds muscle when you're training hard, and keeps you full and satisfied.
A reliable target is 1.6 to 2.2 grams of protein per kilogram of bodyweight. For most people aiming to change their composition, landing around 2g/kg is a smart, simple rule. An 80kg person would target roughly 160g of protein per day.
Step 4: Set your fats
Fats are essential — they support hormones, recovery, and overall health, so they should never be cut too low. A sensible target is 0.8 to 1g of fat per kilogram of bodyweight. For our 80kg example, that's around 64–80g of fat per day.
Step 5: Fill the rest with carbohydrates
Carbs are your training fuel. Once protein and fat are locked in, the remaining calories get assigned to carbohydrates.
Here's how the maths works.
Each gram of protein and carbohydrate provides 4 calories, and each gram of fat provides 9 calories. So you:
Multiply your protein grams by 4
Multiply your fat grams by 9
Subtract both from your total daily calories
Divide what's left by 4 to get your carb grams
It sounds fiddly written out, but it's genuinely just a few sums - and it's exactly the kind of thing that's far easier to let a calculator handle.
Skip the maths — use our calculator
We built a calculator that does all of this for you. Plug in your details, choose your goal, and it returns your calorie target plus a full protein, fat, and carb breakdown in seconds.
Use the PPS Calorie & Macro Calculator here →
The numbers are only the starting point
Here's the part most people miss: these figures are a well-educated starting point, not a fixed prescription. Your body is the real data source. Track your food honestly for two to three weeks, watch how your weight, measurements, and how you look and feel respond, then adjust.
If fat loss has stalled, trim calories slightly. If you're gaining weight too fast, pull the surplus back.
This feedback loop - set, track, adjust - is what separates people who get results from people who spin their wheels. And that's exactly where coaching makes the difference.
At PPS, we take the guesswork out entirely: dialing in your nutrition, building a training plan that matches your goal, and adjusting as you go so you're never left wondering whether you're doing the right thing.
If you'd rather have this handled for you by people who do it every day, get in touch with the team — we'd love to help.