Your Energy Outlook

BMR methods aren't available for this snapshot.

BMR (Basal Metabolic Rate) is the energy your body needs to keep you alive at rest. It powers essential functions like breathing, circulation, temperature regulation, and organ activity. For most people, BMR accounts for the largest share of daily calorie burn.

Why you should care: your BMR anchors your TDEE and every goal target on this page. If your BMR estimate changes, the size of your deficit or surplus changes too, which affects how fast you can lose fat or gain muscle.

The four methods differ in what they assume about your body:

• Mifflin-St Jeor: Uses weight, height, age, and sex. Widely used for general populations and often a solid default.
• Harris-Benedict (revised): An older formula updated in 1984. It can run slightly higher for some people compared to Mifflin.
• Katch-McArdle: Uses lean body mass (requires body-fat data). Helpful if you know your body fat and want a composition-based estimate.
• Cunningham: Also uses fat-free mass and tends to be higher for lean, athletic individuals.

If you have a reliable body-fat estimate, the lean-mass formulas (Katch-McArdle or Cunningham) can be a better fit. If you don't, stick with Mifflin-St Jeor or Harris-Benedict and keep the method consistent so you can track changes over time.

TDEE (Total Daily Energy Expenditure) is the total energy you burn across a typical day. It is the baseline that turns your goal (lose fat, maintain, or gain muscle) into a practical calorie target.

In plain terms: if you consistently eat below your TDEE, you tend to lose weight; if you eat above it, you tend to gain weight. The size of that gap influences how fast things change and how sustainable the plan feels.

This estimate combines your basal metabolism (BMR) with the energy you spend moving and training, and it also accounts for the energy cost of digesting food (thermic effect of food). That is why most goal projections and downstream outputs on this page depend on TDEE.

Why you should care: when your TDEE estimate changes (or is misestimated), every downstream output shifts — fat-loss and muscle-gain targets, predicted weight change, and how aggressive a given deficit or surplus really is for your body.

• How to use it: Pick a goal (lose fat, maintain, or gain muscle) and set your calorie target relative to TDEE. Start conservatively, track your bodyweight trend and performance, then adjust.
• Why it can change: Activity/steps, training volume, bodyweight and lean mass, sleep and stress, diet composition, and day-to-day movement patterns can all shift your real-world burn.
• How to make it accurate: Treat TDEE as an estimate, then calibrate it with consistent logging and a steady routine. If your trend is moving faster or slower than expected, bring your calorie target closer to (or further from) TDEE rather than making big swings.

NEAT (Non-Exercise Activity Thermogenesis) is the energy you expend outside of structured training: walking around, standing, household tasks, commuting, and the countless small movements that make up your day.

In this calculator, NEAT is primarily driven by what you enter in the Activity Planner under Sleep, Sedentary, and Light. Your Moderate and Vigorous entries are treated as exercise (EAT) instead.

• Light: The biggest lever for most people (walking, chores). Small changes add up quickly because they are easy to sustain daily.
• Sedentary: Still burns energy, but less per hour. Reducing long uninterrupted sitting often raises total daily movement even without structured training.
• Sleep:Affects the overall time budget and the model's sleep adjustment. If your routine changes (more/less sleep), NEAT can shift even if training stays constant.

Why this matters: NEAT is usually the most variable part of TDEE. It can rise when you're more active day to day, and it can fall during aggressive dieting or when you're stressed and fatigued. If your scale trend is not matching your expected deficit/surplus, NEAT is often the hidden variable.

EAT (Exercise Activity Thermogenesis) is the energy cost of deliberate training: gym sessions, running, sport, and any other planned workouts.

In this calculator, EAT is driven by your Activity Planner entries under Moderate and Vigorous. Light movement is tracked too, but it contributes to NEAT in the TDEE breakdown (and is shown here for context).

Practical note: EAT is the most programmable component of your TDEE, but it can still vary based on session quality, rest times, pace, and how hard you actually push. If you want your estimate to track reality, keep your weekly training volume consistent and update the Activity Planner when it changes.

TEF (Thermic Effect of Food) is the energy your body spends digesting, absorbing, and processing what you eat. It is not extra exercise burn; it is a real cost of turning food into usable energy and building blocks.

In this calculator, TEF is estimated from your Nutrition Profile selection. The profile sets a TEF factor that adjusts your total expenditure upward to account for digestion costs (conceptually: TDEE = TEE / factor, and TEF = TDEE - TEE).

• Selected profile: Balanced Diet
• What it implies: Mixed intake with roughly 15-25% protein, 40-60% carbs, and 20-35% fat.
• TEF factor: 0.9 (~10% of TDEE)

How to interpret this: higher-protein diets tend to have a higher TEF, while lower-protein patterns and very low intakes reduce it. If your eating pattern changes meaningfully (especially protein intake or whether you are fasting), update the Nutrition Profile so the estimate stays aligned with your inputs.

Energy Availability (EA) is best thought of as your “fuel left over” after training demands. When EA is consistently low, your body has less energy to allocate to recovery, adaptation, and normal physiological functions (including hormone and immune function).

The gauge reflects your estimated EA when eating at maintenance for this session. If you run a larger calorie deficit or increase training volume, EA tends to fall. If you eat closer to maintenance, reduce training load, or improve recovery, EA tends to rise.

Why you should care: low EA often shows up as stubborn plateaus, persistent fatigue, poor sleep, low mood, frequent aches/injuries, and reduced training performance (and in some women, menstrual disruption).

• Female: Low/unhealthy below 30; healthy 30-45; optimal above 45 kcal/kg FFM.
• Male: Low/unhealthy below 25; healthy 25-40; optimal above 40 kcal/kg FFM.

• To improve your EA: Ease up on training volume or add rest days (especially high-intensity cardio), and eat closer to maintenance rather than pushing an aggressive deficit.
• Support recovery: Prioritise sleep, spread protein across meals, and consider adding more carbs around training if workouts feel flat.

Provide a body-fat percentage to unlock EA calculations.

Predicted Muscle Gain Rate estimates the maximum realistic monthly gain given your current bodyweight.

Supply a body-fat percentage to estimate muscle gain potential.

Fat-free mass (FFM) is everything that isn’t fat: muscle, bone, organs, and water. In practice, it’s a proxy for your “lean engine.” Higher FFM usually means better strength potential, a firmer look at a given body weight, and an easier time maintaining your results.

Why you should care: if your FFM is low relative to your body weight, dieting harder often backfires (you end up smaller, flatter, and still not satisfied). Building and preserving lean mass tends to improve how you look, how you perform, and how resilient you feel day-to-day.

The ranges below are shown as a percentage of total body weight and are grouped by age and gender because typical FFM% shifts over time.

• Female under 30: Low below 68%; healthy 75-90%; very high above 90%.
• Female 30-49: Low below 65%; healthy 72-87%; very high above 87%.
• Female 50+: Low below 62%; healthy 69-84%; very high above 84%.
• Male under 30: Low below 75%; healthy 82-95%; very high above 95%.
• Male 30-39: Low below 72%; healthy 79-92%; very high above 92%.
• Male 40-59: Low below 69%; healthy 76-89%; very high above 89%.
• Male 60+: Low below 65%; healthy 72-85%; very high above 85%.

• To improve your FFM%: Build/retain muscle with consistent resistance training and avoid extreme dieting that forces you to lose strength and training quality.
• Nutrition levers: Hit protein consistently, keep deficits moderate when cutting, and use a small surplus when prioritising muscle gain.

Add body-fat percentage to unlock body composition insights.

The fat oxidation limit estimates how much energy your body can supply from stored fat each day. It sets the lowest daily intake before the deficit exceeds what fat stores can cover.

• Estimated limit: —
• Maintenance: —

Why you should care: pushing below this limit can increase fatigue, hunger, and the chance of losing lean mass rather than fat, especially if recovery and protein intake are inconsistent.

Add body-fat percentage data to estimate the fat oxidation limit.

Maximum Muscular Potential (MMP) is an expectations tool: it helps you understand how close your current body weight and leanness are to the “very muscular” end of the spectrum for your height. It’s not a health score or a guarantee of what you personally can achieve.

Why you should care: it helps you choose the right focus. If you’re far from your estimated ceiling, your best results usually come from building muscle (and being patient). If you’re already close, progress is slower and it often makes more sense to prioritise performance, maintenance, or refining body fat.

This calculation is only provided for male profiles in this model.

• Below 80% of your estimated max: Significant room to build (not unhealthy by itself).
• 80-90%: Advanced muscularity with slower gains.
• 90-100%: Near genetic ceiling; progress is incremental.

• To move closer to your MMP: Train with progressive overload, eat enough to recover, and stay consistent for months/years (small changes compound).
• If you’re near the ceiling: Improve performance (strength, reps, work capacity), keep recovery high, and avoid chasing aggressive bulks that add more fat than muscle.

Normalised FFMI is a muscularity score adjusted for height. It helps explain why two people can weigh the same but look very different: higher nFFMI generally means you carry more lean mass for your frame.

Why you should care: if your nFFMI is low, the biggest payoff usually comes from building muscle rather than pursuing more weight loss. If it’s high, your results often come from maintaining muscle while adjusting body fat and performance goals.

• Female: Low below 16; typical 16-20; very high above 20.
• Male: Low below 20; typical 20-25; very high above 25.

• To increase nFFMI: Prioritise progressive resistance training, eat enough to support training quality, and give it time (muscle gain is slow but reliable).
• To protect nFFMI while cutting: Keep lifting hard, avoid crash dieting, and prioritise sleep so you retain lean mass.

Energy Surplus Efficiency converts your muscle gain potential into an estimated caloric surplus that is worth consuming.

Energy surplus efficiency becomes available once body-fat data is supplied.