About

Standard medical BMR calculators often underestimate the caloric needs of active individuals. This tool utilizes the specific parameters outlined by natural bodybuilder and author Tom Venuto. It combines the Harris-Benedict equation with Venuto's distinct Activity Factors, which are tailored for those engaging in structured resistance training and cardio.

Understanding your numbers is the first step to body recomposition. Maintenance is your baseline. A caloric deficit (Fat Loss Zone) or surplus (Muscle Gain Zone) is then calculated as a percentage of this maintenance level, rather than arbitrary fixed numbers.

Formulas

The calculator first determines BMR using the Harris-Benedict formula:

Men: 66 + (13.7 × kg) + (5 × cm) − (6.8 × age)

Women: 655 + (9.6 × kg) + (1.8 × cm) − (4.7 × age)

Total Daily Energy Expenditure (TDEE) is then calculated:

TDEE = BMR × ActivityFactor

Reference Data

Activity Level	Multiplier	Description
Sedentary	1.2	Little or no exercise, desk job.
Lightly Active	1.375	Light exercise/sports 1-3 days/week.
Moderately Active	1.55	Moderate exercise/sports 3-5 days/week.
Very Active	1.725	Hard exercise/sports 6-7 days/week.
Extra Active	1.9	Very hard daily exercise or physical job.

Frequently Asked Questions

While Mifflin is newer, Tom Venuto's methodology specifically calibrates the activity multipliers to work with the Harris-Benedict baselines. Mixing formulas with multipliers from different systems can skew results.

This calculates a moderate caloric deficit of 20% below your maintenance (TDEE). This is generally considered the "sweet spot" for losing fat while preserving lean muscle mass.

No. The Activity Multiplier already accounts for your exercise. Adding exercise calories on top of your TDEE would result in double-counting.