Last updated: September 11, 2026
Step 1: Where You Actually Are
Every plan starts with a baseline, and this is where most people reach for BMI — which is fine, as long as you know what it is. BMI is a screening tool, not a diagnosis. It divides weight by height squared and says nothing about body composition, so a muscular person can read as overweight while someone with very little muscle reads as normal. The BMI Calculator gives you the number, the healthy range it falls into, and BMI Prime (how far you are from the top of that range).
For a more useful picture, add a body composition estimate. The Body Fat Calculator uses the U.S. Navy tape method — neck, waist, and hip measurements — which requires nothing more than a tape measure and tells you something BMI cannot: how much of your weight is lean mass. Pair it with the Ideal Weight Calculator, which returns a range from four clinical formulas rather than one authoritative-looking number. A range is the honest answer here; different formulas disagree because bodies do.
Step 2: How Many Calories You Actually Burn
Your BMR (Basal Metabolic Rate) is what you burn at complete rest — breathing, circulation, temperature regulation, cell repair. It accounts for roughly 60-75% of everything you burn in a day, which is why it is the foundation the rest of the numbers are built on. Multiply it by your activity level and you get TDEE (Total Daily Energy Expenditure) — your maintenance calories, the amount that keeps your weight stable.
The TDEE & BMR Calculator uses the Mifflin-St Jeor equation, which replaced the older Harris-Benedict formula as the clinical standard: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women the same with −161 instead of +5. The activity multiplier is the noisiest input — most people overestimate how active they are — so if your results look wrong after two weeks, adjust that before your weight.
Step 3: How Many Calories to Eat
Once you have maintenance calories, weight loss is a subtraction — and the size of the subtraction is the whole decision. The widely used guidance is a deficit of 300 to 500 calories below TDEE, which works out to roughly 0.5 to 1 kg (1 to 2 lb) per week. For reference: a 500-calorie daily deficit is the classic approximation of 1 lb of fat per week.
| Goal | Daily calories vs TDEE | Typical result |
|---|---|---|
| Maintain | TDEE | Weight stable |
| Lose fat | −300 to −500 | 0.5–1 kg (1–2 lb) per week |
| Gain muscle | +300 to +500 | Strength gain with limited fat gain |
Bigger is not better. A very large deficit is hard to hold, tends to cost muscle along with fat, and drops nutrient intake along with calories. One guardrail worth keeping: do not eat below your BMR without medical supervision — that is the level your body needs just to run itself. The Calorie Deficit Calculator applies these limits to your own numbers and shows the timeline to your goal weight, so you can see the trade-off between speed and sustainability before you commit to it.
Step 4: Protein — The Number That Protects Muscle
Calories decide whether you lose weight. Protein decides what that weight is made of. In a deficit your body is short on energy and will happily break down muscle for it unless you give it reason not to. The RDA — 0.8 g per kg of body weight — is set to prevent deficiency in sedentary adults, not to protect muscle while dieting, which is why the useful range is well above it:
| Goal | Protein per kg body weight | For a 70 kg person |
|---|---|---|
| Sedentary (RDA) | 0.8 g/kg | 56 g/day |
| Active / light fitness | 1.2–1.6 g/kg | 84–112 g/day |
| Muscle gain | 1.6–2.2 g/kg | 112–154 g/day |
| Weight loss | 1.6–2.4 g/kg | 112–168 g/day |
Two practical details: spread it out — 20-40 g per meal spaced a few hours apart does more than the same total in one sitting — and expect it to make the diet easier, because protein is the most satiating macronutrient. Intakes up to about 2.5 g/kg are generally considered safe in healthy people; if you have kidney disease, talk to your doctor first. The Protein Calculator gives your daily target and the per-meal split.
Step 5: Carbs and Fat Fill the Rest
Protein is set from body weight, not from a percentage — that is the key ordering decision. Once it is fixed, the remaining calories are divided between carbohydrate and fat, and the honest truth is that the split matters far less than hitting your calories and your protein. Preference and training style decide it: more carbohydrate suits high training volume, more fat suits lower-carb preferences or appetite control.
There are floors worth respecting rather than going as low as possible on either — dietary fat supports hormone production and fat-soluble vitamin absorption, and carbohydrate is the primary fuel for hard training. The Macro Calculator converts your calorie target into grams of each, so the numbers are something you can actually plan meals around instead of percentages you have to convert in your head.
Step 6: Is It Actually Working?
Daily body weight is a noisy measurement. Sodium, carbohydrate intake, hydration, hormonal cycles, and yesterday's hard session can move the scale 1-2 kg without any change in fat. Reading a single morning's number as "progress" is how people abandon a plan that is working perfectly.
What you want is the trend. Weigh at roughly the same time, log it, and then read the 7-day average — that is what the Weight Loss Tracker shows, because a week smooths out the day-to-day swings while still responding fast enough to catch a real stall. Judge your plan on the weekly direction, adjust at most every two weeks, and change one variable at a time so you know which one did something.
When the Scale Stops Moving
A plateau is normal, and it usually has one of three causes — none of which is "my metabolism is broken":
- Your deficit shrank. Losing weight lowers BMR and the cost of moving, so the intake that used to be a deficit becomes maintenance. Recalculate with the TDEE calculator at your current weight rather than the weight you started at.
- Intake drifted up. Portions creep, oils and drinks stop being counted, weekend eating stops being logged. Tracking carefully for one week — the tracker plus honest logging — usually finds it.
- Water is masking fat loss. This can hide progress for one to three weeks, especially around a hard training block or a high-salt stretch. If the 7-day trend is flat but your measurements and strength are improving, you are probably still losing fat.
The fix is usually a small adjustment, not a drastic one: take 100-200 calories off the target, or add activity rather than cutting further, and give it two weeks before judging. Cutting hard in response to a two-week stall is how a working plan turns into a crash diet.
If you want the shortest useful path: start with the TDEE & BMR Calculator — every other number derives from it — then set your intake with the Calorie Deficit Calculator, lock in protein with the Protein Calculator, split the rest with the Macro Calculator, and start logging in the Weight Loss Tracker so you are judging the trend instead of the noise.
Sources: Mifflin & St Jeor (1990) basal metabolic rate equation; International Society of Sports Nutrition (ISSN) position stand on protein and exercise (2017); World Health Organization protein and energy requirements; Academy of Nutrition and Dietetics; US Navy circumference method for body fat estimation; CDC and NIH guidance on BMI as a screening tool. These tools provide general estimates for healthy adults and are not medical or dietary advice. Individual needs vary — consult a healthcare professional or registered dietitian, particularly if you are pregnant, managing a medical condition, or planning a deficit larger than the ranges above.