Macro Calculator

Mifflin-St Jeor calculates BMR based on age, gender, weight, and height. It's accurate for most people and doesn't require knowing body fat percentage. Katch-McArdle uses lean body mass (total weight minus fat mass) and is more accurate if you know your body fat %. The difference is typically 50-150 calories per day. If you enter body fat %, the calculator will use Katch-McArdle; otherwise it defaults to Mifflin-St Jeor.

No, body fat % is optional. The Mifflin-St Jeor formula (which doesn't need body fat %) is accurate for most people. However, if you're very lean (<15% men, <25% women) or have a lot of muscle mass, knowing your body fat % and using Katch-McArdle will give you 5-10% more accurate results. You can measure body fat with calipers, DEXA scan, or bioelectrical impedance scales.

Aim to hit your protein target 80% of the time (5-6 days per week). On days you fall short, try to get within 20g of your target. Protein is the most important macro for preserving muscle during fat loss and building muscle during a bulk. If you consistently struggle, try protein shakes, Greek yogurt, or lean meats at every meal. Remember: total weekly protein matters more than daily perfection.

For most people, keeping macros consistent every day is simpler and works just as well. However, advanced lifters sometimes use 'carb cycling' — eating more carbs on workout days and fewer carbs on rest days. If you want to try this, reduce carbs by 50-100g on rest days and replace those calories with fat. Keep protein the same every day regardless of training.

Counting macros is superior if you care about body composition (muscle vs fat). Calories determine whether you gain or lose weight, but macros determine whether that weight is muscle or fat. For example, losing weight on low protein means you'll lose more muscle. Gaining weight on low protein means more fat gain. If you're short on time, prioritize: 1) Total calories, 2) Protein, 3) Carbs and fat can be flexible.

Start with an 80/20 approach: track 80% of your meals (pre-planned meals) and be flexible with 20% (eating out, social events). Pre-log your day the night before so you're not constantly thinking about food. Use the same meals repeatedly — 'boring' meal plans are easier to track and stick to. Take diet breaks every 8-12 weeks where you just maintain weight without strict tracking. Remember: macros are a tool, not a lifestyle prison.

For muscle building, protein is king — aim for 0.8-1g per lb of body weight. The classic bulk split is 40% carbs, 30% protein, 30% fat, but you can push carbs higher (50%) if you train hard and need the energy. Don't go below 20% fat as it affects hormone production. Total calories matter most: eat 10-20% above your TDEE (300-500 cal surplus). Smaller surpluses mean slower, leaner gains; larger surpluses mean faster gains but more fat.

Yes, but only under specific conditions: you're a beginner lifter, returning after a break, or significantly overweight. This is called 'body recomposition.' Keep protein very high (1g per lb), eat at maintenance or a small deficit (-200 to -300 cal), and lift weights 3-5x per week. Progress is slower than pure cutting or bulking, but you improve body composition without extreme dieting. Most people see better results choosing one goal at a time.

Fiber (14g per 1,000 calories) improves digestion, keeps you full, and stabilizes blood sugar — especially important on high-protein diets. Water (0.5 oz per lb of body weight) prevents dehydration from increased protein intake, supports performance, and helps with appetite control. Most people under-consume both, which can sabotage fat loss and muscle building despite hitting macros perfectly.

Recalculate every 10-15 lbs of weight change or every 8-12 weeks, whichever comes first. As you lose weight, your TDEE drops and you'll need to reduce calories to keep losing at the same rate. As you gain weight (muscle), your TDEE increases. Also recalculate if your activity level changes significantly (new job, training program, injury). Track your weight weekly and adjust if you're not seeing expected progress after 3-4 weeks.

Protein per lb (or kg) measures how much protein you eat relative to your body weight. Research suggests 0.7-1.0g per lb (1.6-2.2g per kg) for active people trying to build or maintain muscle. For fat loss, aim for 0.8-1.2g per lb to preserve muscle. For general health, 0.36g per lb (0.8g per kg) is the minimum RDA. The 'Protein Analysis' toggle shows exactly where your intake falls relative to these benchmarks.