Meal Prep Math: Turning Macros Into Actual Meals

Hitting your macros across a whole week is a math problem. Most people try to solve it one meal at a time — at the moment of eating — which is the worst time to do math. Tired, hungry, distracted, with a phone showing a list of grams you're meant to compose into a plate of food.

The cleaner approach is to solve the math before the week starts. You're not deciding what to eat in the moment. You're following a plan you already made when your brain was working. Here's how that math actually goes.

Step one: lock the daily protein target

Use the macro calculator to get your target. For most active adults, that's somewhere between 140 and 220g of protein per day. Pick a round number you can hit consistently. Call it your protein floor.

From here on, this number is non-negotiable. Every meal-prep decision works backward from it.

Step two: divide protein across three to four meals

If your target is 180g, divide it: 3 meals at 50g + 1 snack at 30g, or 4 meals at 45g. That's the protein architecture of your day. Now each meal has a known protein job.

Look at the next meal you're going to eat and ask: "Does it deliver ~45g of protein?" If yes, you're on track. If no, what do you need to add? Two eggs? A second chicken thigh? A scoop of protein powder in a smoothie? Adjust at the meal level — don't try to "make up for it" later.

Step three: spend the rest of your calorie budget on carbs and fat

Your daily target (call it 2,400 kcal). Protein at 180g = 720 kcal. That leaves 1,680 kcal for carbs + fat.

For a balanced split: aim for ~50% from carbs, ~25% from fat. That's 210g of carbs (840 kcal) and 47g of fat (~420 kcal). Round the numbers; the calculator gives you a good split per goal.

Now you've got your daily plate budget: 180p / 210c / 47f. Every meal is just allocating slices of that budget.

Macros are a budget. Plan the spend before you sit down to spend it. You wouldn't negotiate rent every time you opened the fridge.

Step four: write meals on paper, by macros

Before going to the grocery store, write out your 7 days like a budget. For example:

• Breakfast: 4 eggs + 4 whites + 1 cup oats + 1/2 banana = 35p / 45c / 18f
• Lunch: 6 oz chicken + 1 cup rice + 1 cup vegetables + 2 tbsp olive oil = 50p / 50c / 14f
• Snack: 1 cup Greek yogurt + 1 scoop protein + berries = 45p / 25c / 0f
• Dinner: 6 oz salmon + 1 cup rice + 2 cups vegetables + lemon = 40p / 50c / 18f
• Daily total: 170p / 170c / 50f ≈ 1,810 kcal — adjust upward if needed.

Tweak the portions to hit your number. The point isn't perfection on day one. The point is having a written plan that hits within ~10% of your target. After two days of cooking from it, you'll know exactly what to adjust.

Step five: turn the meals into a shopping list

Multiply up. If you need 6 oz of chicken at lunch every day, that's 42 oz (~2.6 lbs) of chicken for the week. If breakfast eats 6 eggs and 4 whites per day, that's 42 eggs and a carton of whites. Round up — over-prep is cheaper than under-prep.

Now your shopping list isn't a guess. It's a derivation of your math. Walk into the grocery store, buy the math, walk out.

Step six: cook the math on Sunday, assemble it during the week

Cook the proteins in bulk. Cook the carb base in bulk. Roast the vegetables in bulk. Now during the week, every meal is a 5-minute assembly job, and the macros are already decided for you. No more "what should I eat?" — only "how much of what's already cooked?"

See the survives-Tuesday meal prep system for more on this side of it.

The macro shorthand worth memorizing

After a month of doing this, you'll know these without looking them up:

• 4 oz cooked chicken breast — 35p / 0c / 4f
• 4 oz cooked lean ground beef — 28p / 0c / 12f
• 1 cup cooked rice — 4p / 45c / 0f
• 1 medium sweet potato — 2p / 25c / 0f
• 1 large egg — 6p / 0c / 5f
• 1 cup non-fat Greek yogurt — 22p / 10c / 0f
• 1 scoop whey isolate — 25p / 2c / 1f
• 1 tbsp olive oil — 0p / 0c / 14f

Memorize those eight, and you can build a meal in your head before you walk into the kitchen.

The simple version

Meal prep math isn't hard. It's just a different muscle from what most people use. Plan the spend on Sunday. Cook the inputs. Assemble through the week. Stop trying to do the math at the moment of eating.

If you'd rather not do the math at all, Mero does this kind of weekly allocation automatically against your training calendar. The version here is the manual version. The principles don't change.