The decision
Choosing your macro split without guessing
On a 2,000 kcal target, switching from the balanced split to keto drops your carb allowance from 200 g to 25 g while the calorie number on screen never moves. That gap is the problem this page solves. The split you pick and the goal you set are two separate decisions, and most calculators fold them into one dial so you cannot tell which one is doing the work. Macra keeps them apart deliberately, so what follows is the order to make those decisions in, and how to land on grams you can actually eat.
Order of operations
Your goal comes before your split
Your goal sets the size of the calorie target. The split only decides how that target gets carved into protein, carb, and fat grams.
Get those backwards and you end up tuning ratios against a calorie number that is still wrong. So settle the goal first: are you cutting, holding, or gaining? That answer picks your deficit or surplus, which fixes the calorie target, and only then does the split have a stable number to divide. One design choice makes this safe to explore. In Macra, switching the dietary style never touches the calorie target, it only re-divides the grams underneath it. We built it that way because watching the headline calories jump every time you compared Balanced against Keto made the two decisions feel coupled when they are not, and people would talk themselves out of a sensible deficit over a ratio change that never moved their actual energy number.
Sizing the target
Matching a deficit or surplus to the goal
A cut applies a deficit to your maintenance number (TDEE), the figure Macra estimates with the Mifflin-St Jeor equation published in 1990:
BMR = 10·kg + 6.25·cm − 5·age + s (s = +5 men, −161 women) TDEE = BMR × activity factor (×1.2 sedentary … ×1.9 extra active)
Macra offers three cut paces: mild −250 kcal/day (about 0.5 lb per week), moderate −500 (about 1 lb per week), and aggressive −750 (about 1.5 lb per week). A gain applies a surplus, and here there are only two paces: mild +250 (about 0.5 lb per week) and moderate +500 (about 1 lb per week). There is deliberately no aggressive-bulk tier. We left it off because a faster surplus mostly buys fat rather than muscle, and +500 is already more than most people can turn into lean mass in a week, so a third, larger tier would only have handed back a number no one should chase.
Maintenance is a delta of zero, so it is never floored or adjusted.
A deficit is the one direction that can hit a guardrail. If an aggressive cut on a low maintenance number would drop the target below 1,200 kcal/day, Macra holds it at 1,200 rather than printing something lower. We floor at a flat 1,200 instead of a percentage of TDEE for a reason: a percentage floor scales down with the person, so someone small enough to need the protection is exactly who it would keep pushing further down. A surplus and maintenance are never floored, because only a deficit can pull the target under maintenance in the first place.
Reading the splits
Let training frequency pick your carb share
Carbs are the macro that swings most between splits, so let how often you train decide the carb share. Carbs are your fastest fuel for hard sessions, so the more you train, the more of your target should sit there. Cutting carbs frees those calories for protein and fat, which is exactly what the low-carb and keto styles do.
| Style | Protein | Carbs | Fat | Best when |
|---|---|---|---|---|
| Balanced | 30% | 40% | 30% | Hard training, five or more days a week |
| High-protein | 40% | 35% | 25% | Three or four moderate days; suits a cut |
| Low-carb | 40% | 20% | 40% | Low activity, or fewer carbs preferred |
| Keto | 25% | 5% | 70% | Carbohydrate wanted at a token amount |
If you train hard five or more days a week, or stack back-to-back sessions, keep carbs high and start at Balanced. Three or four moderate days a week fit High-protein, which trims carbs a little and pushes protein up. One or two easy days, or a personal preference for fewer carbs, point to Low-carb. Keto is the choice only when you specifically want carbohydrate at a token 5 percent, not a side effect of picking a lower-carb style by accident.
The floor, then the path
The protein floor every split has to clear
Protein is the macro you check in grams, not percent, because it is what protects muscle while the scale moves. Even Keto’s 25 percent share is there to clear a floor, not to hit a ratio, and a 25 percent share of a large target can out-gram a 40 percent share of a small one. A workable floor for most people is roughly 1.6 g per kg of body weight; below that, a cut starts eating into lean mass instead of fat. Every split divides the target the same way, at 4 kcal/g for protein and carbs and 9 kcal/g for fat:
2,000 kcal, Balanced 30/40/30: protein 30% ÷ 4 = 150 g · carbs 40% ÷ 4 = 200 g · fat 30% ÷ 9 ≈ 67 g
Here is the whole choice as one ordered path:
- Set your goal. Cutting, go to 2. Maintaining, go to 3. Gaining, go to 4.
- Pick a cut pace: mild
−250(about 0.5 lb/week), moderate−500(about 1 lb/week), or aggressive−750(about 1.5 lb/week). Before you commit, read the protein tile in grams: if it lands under about 1.6 g/kg, move to a higher-protein split before cutting calories further. Then go to 5. - Maintenance holds at TDEE with no delta. The protein floor still applies. Go to 5.
- Pick a gain pace: mild
+250(about 0.5 lb/week) or moderate+500(about 1 lb/week). There is no aggressive tier here. Go to 5. - Pick the split by carb tolerance. Train hard 5+ days/week, Balanced (30/40/30), highest carbs. Train 3–4 days, High-protein (40/35/25), which usually gives the most protein grams and suits a cut. Low activity or fewer carbs preferred, Low-carb (40/20/40), protein still at 40 percent. Want carbs at a token amount, Keto (25/5/70), and confirm that 25 percent still clears your protein floor in grams.
At every branch, read protein in grams, not as a percentage. The percentage is only its share of the calorie target, so a floor set in grams is the one that actually protects you.
The last knob
When the split stops mattering
The split is a second-order decision.
Once your calorie target and your protein floor are set, whether the remaining calories tilt toward carbs or fat changes how training feels and how full you stay between meals, but it does not change the rate the scale moves. Total calories drive that. So if you are flipping between Balanced and Low-carb every few days chasing a faster result, you are turning the wrong knob: the deficit moves weight, and the split only decides what that same deficit feels like day to day. The one caveat worth ending on is a display detail. The grams Macra shows are rounded to whole numbers, and the percentages are rebalanced with a largest-remainder pass so protein, carb, and fat total exactly 100 rather than 99 or 101. That rounding is cosmetic: it never shifts your calorie target. And because every number is computed in your browser and nothing is saved, you can run all five branches above back to back without anything being stored. Treat the split as the last knob you turn, not the first.
Common questions
Frequently asked questions
What are macros, and why do they matter once I know my calories?
Macros are the three nutrients that carry all the energy in your food: protein, carbohydrate, and fat. Calories tell you how much you are eating; macros tell you what those calories are made of. Two 2,000-calorie days can leave you feeling and performing very differently depending on whether they lean toward protein and carbs or toward fat. Macra takes your daily calorie target and splits it into grams of each so you have a concrete number to aim at rather than a single calorie figure.
How does the Mifflin-St Jeor formula estimate my resting burn?
Mifflin-St Jeor estimates your basal metabolic rate, the energy your body uses at complete rest to keep your heart, lungs, and cells running. It weighs four inputs: 10 times your weight in kilograms, plus 6.25 times your height in centimeters, minus 5 times your age, then plus 5 for men or minus 161 for women. It is a population average published in 1990 and widely used because it tracks measured resting burn more closely than the older Harris-Benedict equation for most adults. Your own number can sit above or below the estimate.
What do the five activity multipliers actually mean?
Your resting burn only covers lying still. The activity multiplier scales it up to your total daily energy expenditure, which includes walking, training, and everything else you do. Macra uses five steps: sedentary at 1.2 for a desk day with little movement, lightly active at 1.375 for light exercise one to three days a week, moderately active at 1.55 for three to five days, very active at 1.725 for hard training six or seven days, and extra active at 1.9 for hard training plus a physical job. Pick the row that matches a normal week, not your best one.
How does choosing lose, maintain, or gain change my daily target?
Maintain leaves your target equal to your total daily energy expenditure, the calories that hold your current weight. Lose subtracts a deficit so your body draws on stored energy: mild is about 250 calories a day, moderate about 500, and aggressive about 750, which map roughly to half a pound, one pound, and one and a half pounds a week. Gain adds a surplus of about 250 or 500 for a slower or faster build. Macra floors any deficit at a safe minimum so an aggressive cut on a low burn never drops your target to an unworkable number.
Which dietary-style split should I pick?
The split only decides how your fixed calorie target is divided, so no split is right or wrong on its own. Balanced (30/40/30) suits most people and everyday training. Low-carb (40/20/40) trims carbohydrate in favor of protein and fat, which some prefer for appetite control. High-protein (40/35/25) pushes protein highest and tends to pair with strength work and a cut. Keto (25/5/70) drops carbohydrate to a token amount and leans on fat. Switching styles in Macra never moves your calorie number, only the grams beneath it, so you can compare them side by side in seconds.
Does Macra store or send the numbers I enter?
No. Every calculation runs in your browser as you type, with no server call and no account. Your age, height, weight, and goals are never uploaded, saved to a database, or shared. The only thing Macra keeps between visits is your unit preference (metric or imperial) and your light or dark theme choice, both stored locally on your own device. Close the tab and the rest is gone. That is why there is no email box, no signup, and no popup between you and your numbers.
Ready to see your own numbers?
Use the CalculatorRelated tools
Where to take these numbers next
The rest of the gym-math shelf runs the same way: one screen, no accounts, nothing saved.
Onemax
A weight and a rep count in, an instant one-rep max estimate out, with three published formulas to compare.
Coefflift
Scores a lift pound for pound with Wilks and DOTS side by side, and shows the math behind both.
Plateside
Tells you which plates go on each side of the bar for any target weight, and what the loaded bar adds up to.
Milemarq
Enter two of pace, time, and distance for a run and it solves the third, with per-mile and per-kilometer splits.