Calculating cutting macros means dividing a planned calorie intake between protein, fat and carbohydrate. The aim is to support training and retain muscle while gradually reducing body fat. There is no single percentage split that suits everyone.
The calculation below is a worked example for a healthy adult, not a personal calorie prescription. Your own needs depend on your body size, activity, starting point and health.
1. Estimate your maintenance calories
Maintenance is the average intake at which your weight is broadly stable. An online calculator can provide a starting estimate, but your recent food intake and weight trend help show whether that estimate fits you.
If tracking suits you, record your usual intake and compare average body weight over a couple of weeks. Use similar weighing conditions. One high or low reading can reflect factors other than a change in body fat.
2. Choose a modest starting deficit
A calorie deficit means eating less energy than you use over time. Start with a change you can sustain rather than cutting as much as possible immediately.
For this example, suppose an adult maintains weight at approximately 2,500 calories per day. A 10% reduction gives a starting intake of 2,250 calories. This is an illustration, not a rule that every person should eat that amount.
There is no need to deepen the deficit automatically every few weeks. Review what is happening before making another reduction. Persistent fatigue, poor recovery or declining training performance are reasons to reassess the approach.
3. Set protein in grams
Establish protein before dividing the remaining calories. Research on lean, resistance-trained bodybuilders dieting for competition suggests relatively high protein needs, with recommendations expressed per kilogram of lean body mass. That specialist context should not be confused with a universal target for all adults. Read the nutrition review by Helms and colleagues.
Our calculation uses an illustrative target of 160 grams of protein. This is an input chosen to demonstrate the arithmetic, not an amount everyone needs. Protein provides approximately four calories per gram, so 160 grams accounts for 640 calories.
4. Allocate dietary fat
Next, choose a fat intake that leaves room for the rest of your diet. Avoid treating dietary fat as something to eliminate. Foods such as olive oil, nuts, seeds, eggs and fish can contribute to a varied eating pattern.
For the example, use 70 grams of fat. At approximately nine calories per gram, that accounts for 630 calories. Your personal allocation can differ; there is no requirement to change your fat percentage every time you have a rest day.
5. Calculate carbohydrate from the remainder
Subtract protein and fat calories from the total, then divide by four to convert the remaining calories into grams of carbohydrate.
Carbohydrate grams = [daily calories − (protein grams × 4) − (fat grams × 9)] ÷ 4
For this example: [2,250 − (160 × 4) − (70 × 9)] ÷ 4 = 245 grams of carbohydrate.
| Macro | Daily grams | Calories per gram | Daily calories |
|---|---|---|---|
| Protein | 160 | 4 | 640 |
| Fat | 70 | 9 | 630 |
| Carbohydrate | 245 | 4 | 980 |
| Total | 2,250 |
Check that your numbers add up before using them. Food labels and tracking apps may show small differences because of rounding, fibre and other components.
Turn the numbers into ordinary meals
Distribute your intake in a way that fits your day. Build meals around protein-rich foods, add carbohydrate portions that support your training, and include fruit, vegetables and sources of fat. You do not need to hit every gram perfectly each day.
For affordable food ideas, see our guide to protein sources. Keep the emphasis on meals you can prepare and enjoy repeatedly.
Adjust from the trend
Review average weight, training performance, hunger and recovery together. If you are progressing comfortably, you do not need to change the plan simply because another week has passed.
If the trend has stalled over several weeks, check how closely your actual intake matches the estimate before making a small adjustment. If you are struggling to recover or the diet is becoming difficult to manage, reassess the deficit rather than pushing it harder.
Macro tracking is optional. If it encourages restrictive or compulsive eating, use a less numerical approach with support from a registered dietitian. The goal is a sustainable eating pattern, not perfect numbers at any cost.