Formulas, assumptions, and limitations

The serving converter scales supplied nutrients by amount eaten / label weight. The label basis may be a serving, 100 g, or the full package. Weights must use grams and the same preparation state.

The recipe nutrition calculator sums those scaled ingredient values. It divides totals by serving count or finished weight to calculate per-serving and per-100 g nutrition. Missing nutrients remain unknown, including a recipe total if any ingredient lacks that nutrient. Zero must be entered explicitly. Discarded cooking liquid, fat, and uneven mixtures are not modeled.

The label comparison tool scales both foods to one chosen weight. Optional cost equals package price × comparison weight / package food weight. Prices must share a currency; selecting a currency only changes formatting. The tool does not assign a health score.

The meal-prep planner divides batch weight and nutrient totals by the number of equal containers, or allocates each custom container a weight-proportional share. Custom allocations cannot exceed the batch; any remainder is shown separately. Personal printable portion cards are not commercial nutrition labels or storage-safety guidance.

The raw-to-cooked converter uses measured weights for the same batch. Cooked portion × raw batch / cooked batch gives raw equivalent; the reverse calculation gives cooked equivalent. It does not use universal yield factors or estimate nutrient retention.

These five tools run without signup. Optional saves stay in browser storage on the current device and are removed when site data is cleared. Recipe transfers use this browser tab. Entered food names, values, and results are excluded from tool analytics. Arithmetic uses unrounded numbers; displayed results round to one decimal, and costs to the currency precision.

The recipe portion calculator multiplies a user-supplied recipe calorie total by the portion weight divided by the finished batch weight. Calories per 100 g use the same total divided by batch weight, multiplied by 100.

Both weights must be positive, finite values in grams, and the portion cannot exceed the batch. Calories must be finite and nonnegative. Container weight is excluded. The calculation assumes an even distribution of ingredients and that the supplied calories represent the finished food; it cannot account for discarded ingredients or uneven portions.

No food database is queried. The page shows a fictional worked example and explains how to obtain inputs. Outputs are estimates based on supplied totals and weights.

The protein cost calculator multiplies servings per package by protein grams per serving, then divides package price by that protein total. Multiplying by 25 provides a shared comparison amount.

Prices must be finite and nonnegative. Servings and protein amounts must be finite and positive. Fractional servings are supported. The currency selector formats values; it does not convert between currencies or fetch prices.

Results compare price only. They do not recommend protein intake, score food quality, or account for waste and preparation costs. Label values must use matching serving and preparation bases. The FDA label guide supports the serving and nutrient interpretation used by both food-planning tools.

The TDEE calculator first estimates basal metabolic rate with the Mifflin-St Jeor equations. It uses weight in kilograms, height in centimeters, age in years, and the selected sex field:

Estimated TDEE is the rounded BMR multiplied by the selected activity factor:

The activity selection is subjective and can be the largest source of error. The result is an estimate of average daily energy use, not a direct metabolic measurement.

The macro calculator uses the entered or estimated TDEE. Its current goal adjustments are TDEE minus 500 calories for weight loss, TDEE for maintenance, and TDEE plus 300 calories for weight gain.

The tool blocks a weight-loss example when subtracting 500 would produce a value below its 1,200-calorie planning guardrail. It does not silently replace that requested scenario with a different deficit.

It then applies the selected fixed macro ratio and converts protein and carbohydrate calories at 4 calories per gram and fat calories at 9 calories per gram. The available presets are starting points, not individualized requirements.

The calorie-deficit calculator converts the selected weekly loss rate using approximately 7,700 calories per kilogram, divides that amount by seven, and subtracts the resulting daily deficit from estimated TDEE. Its timeline divides the weight difference by the selected weekly rate.

The current implementation blocks a scenario when its calculated target would fall below the tool's 1,200-calorie planning guardrail. That product limit is not a personalized safety determination, and the arithmetic assumes a steady rate that real weight change rarely follows exactly.

The walking calculator estimates intensity from walking speed and incline. Flat-walking values are interpolated from a stored MET table. For an incline of 5% or more, the implementation also calculates oxygen cost from speed and grade with the ACSM walking equation and uses the higher resulting estimate. Below 5%, it moves in a straight line from the flat-walking value to the 5% value, so each incline step raises the estimate.

Distance and duration are derived from the chosen speed. Step conversion currently assumes 2,000 steps per mile. The MET formula produces an estimated total energy cost for the activity period, not a personalized measurement of net active calories above rest.

• The TDEE-based tools accept ages 18 through 100 and are not designed for children.
• Manual-TDEE modes require confirmation that the user is at least 18.
• Accepted inputs are 20 to 320 kg for weight, 90 to 275 cm for height, and 0.05 to 1 kg per week for the loss-rate control.
• TDEE planning inputs must be between 1,200 and 10,000 calories per day. The TDEE estimator can display a lower equation output because an energy-expenditure estimate is not an intake recommendation.
• Outputs depend on the accuracy and meaning of the entered values.
• Population equations cannot capture every difference in body composition, health, medication, fitness, terrain, or metabolism.
• Rounding and fixed assumptions make the result easier to use but less precise.
• Projected dates and rates are planning illustrations, not guarantees.

• Mifflin et al. (1990), predictive equation for resting energy expenditure
• National Institute of Diabetes and Digestive and Kidney Diseases Body Weight Planner, which uses a dynamic adult model rather than Kalo's simplified linear timeline
• 2024 Adult Compendium of Physical Activities

The activity multipliers, fixed goal adjustments, 7,700-calorie-per-kilogram conversion, input bounds, and 1,200-calorie guardrail are transparent product assumptions. They should not be interpreted as individualized clinical recommendations or as conclusions established by the references above.