Nutrition
Macro Cycling Calculator
Calculate different macros for training days and rest days with carb cycling for recomp, lean bulk, or cut goals.
Result
- Your TDEE is estimated as if you were a 30-year-old man of 175 cm at your weight and activity. Enter your own (the TDEE calculator gives it) for a plan that fits you.
- No body fat given, so lean mass assumes 20% body fat; protein is set per kg of lean mass.
Training day vs rest day macros
Protein stays constant; carbs run higher on training days, fat runs higher on rest days.
How to use it
- Enter your bodyweight and optionally body fat percentage. Add your known TDEE or select an activity level for an estimate. Choose your training days per week and goal (recomp, lean bulk, or cut).
- Read the side-by-side training day vs rest day macro breakdown. Training days feature higher carbs for performance. Rest days shift calories toward fat while keeping protein constant.
- Check the macro distribution bar on each card to visualize the carb/fat ratio shift between day types. Protein stays the same on both days on purpose: muscle protein synthesis stays raised for a day or more after resistance training, so rest days need it too.
- Review the weekly average calories in the summary. This is the number that matters most for body composition over time; the day-to-day split only moves fuel toward the days you train.
- Recalculate when bodyweight changes by 3+ kg, when switching between goals, or every 4-6 weeks during an active cut or bulk to adjust for metabolic adaptation.
Questions people usually ask
What is macro cycling?
Macro cycling (also called calorie or carb cycling) means eating different amounts on training days and rest days: more carbohydrate on training days to fuel the sessions, relatively more fat on rest days, and the same protein every day, because muscle protein synthesis stays raised for a day or more after resistance training. The weekly total is what drives weight change.
Does macro cycling work better than fixed macros?
Not for fat loss itself: at the same weekly calories and protein, there is little evidence that cycling beats a fixed daily target, and protein timing had no significant effect once total intake was accounted for (Schoenfeld 2013). Its real benefits are practical: more fuel for hard sessions, and training days that feel less restrictive during a cut, which helps some people stick with it.
Why is protein the same on both days?
Muscle protein synthesis remains elevated for 24-48 hours after resistance training, meaning rest days are active recovery days at the cellular level. Dropping protein on rest days reduces the raw material available for muscle repair. The Morton et al. (2018) meta-analysis of 49 studies with 1,863 participants showed that constant high protein intake of 1.6-2.2 g/kg/day maximizes lean mass gains regardless of distribution pattern. There is no evidence that cycling protein between training and rest days offers any advantage over keeping it constant.
What if my rest day calories seem too low?
If rest day calories drop below your estimated BMR or push dietary fat below 0.3 g/lb bodyweight (approximately 0.7 g/kg), the deficit is too aggressive and risks hormonal disruption — particularly testosterone in men and menstrual function in women. Solutions: reduce the training day surplus to create a smaller differential, accept a smaller rest day deficit, or add one extra rest day at training-day calories. Sustainability matters more than mathematical optimality. A protocol you abandon after 3 weeks produces worse results than a slightly suboptimal one you maintain for 12 weeks.
How many grams of carbs should I add on training days?
A typical training day surplus is 30-50g of additional carbs compared to rest days, primarily consumed in the pre-workout meal (2-3 hours before) and post-workout meal (within 2 hours after). For heavy leg days or high-volume sessions, you can increase the differential to 50-80g. The carbs should come from starchy sources (rice, potatoes, oats) rather than sugars for sustained glycogen replenishment. Rest day carbs should focus on fiber-rich vegetables and moderate portions of whole grains rather than being eliminated entirely.
Should I cycle fats too, or just carbs?
Usually yes: when carbs rise on training days, fats come down to keep calories on target, and the reverse on rest days. Training days get more carbohydrate to fuel hard sessions; rest days carry more fat. Keep fat at or above 20% of calories on any day, the bottom of the Institute of Medicine's 20-35% acceptable range for adults.
Is macro cycling useful during a bulk?
Less so. During a caloric surplus (bulk), glycogen stores are typically full regardless of daily distribution, so the performance benefit of extra training-day carbs is minimal. Macro cycling shows the clearest benefit during a cut (caloric deficit) or recomposition (maintenance), where strategically placing more calories on training days can preserve performance and muscle while allowing a steeper deficit on rest days. During a lean bulk with a small 200-300 calorie surplus, cycling can help limit fat gain by concentrating the surplus on days when partitioning toward muscle is most favorable.
How do I calculate my TDEE for macro cycling?
Start with a standard TDEE estimate (use the TDEE Calculator on this site). For macro cycling, the weekly average of training day + rest day calories should equal your TDEE target. For example: if TDEE is 2,500 and you train 4 days/week, you might eat 2,700 on training days and 2,230 on rest days. The weighted average: (4 × 2,700 + 3 × 2,230) / 7 = 2,498, which matches your target. Adjust based on 2-week body weight trends — if weight isn't moving in the desired direction, adjust total weekly calories, not just the distribution.
Is this tool free and private?
Yes. All calculations run client-side in your browser. No data leaves your device. No signup required.
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Articles
- 7 min read Female Athlete Formula Suite: A 30-Year-Old in Regular Cycle
Female athlete formulas for 65 kg, 168 cm, 24% body fat, regular cycle. The luteal-versus-follicular caloric drift and where male equations fail.
- 7 min read Macro Cycling for an 80kg Male Recomp at 2500 kcal TDEE
Macro cycling for an 80 kg male recomp: 2600 kcal training days, 2200 kcal rest. Protein 131 g flat, carbs 239-375 g, fats 64-80 g counter-cycle.
- 7 min read Cycling FTP Zones: 250W at 75kg, 3.33 W/kg Walkthrough
Cycling power zones for a 250W FTP / 75kg rider: 3.33 W/kg trained category, Z2 endurance 140-188W, Z4 threshold 228-263W, Z5 VO2max 265-300W.
Use it from an agent or code
Any agent can run this calculator by URL: put the inputs in the query string and get JSON back, with the inputs that used defaults and a line to cite (add format=md for markdown). MCP clients reach it through https://aifithub.io/mcp.
In code, import the same module; it runs where you import it, with no request or key.
import { compute } from "https://aifithub.io/engines/macro-cycling-calculator.js";Input and output contract, TypeScript types and the guide for agents.