Plain-English glossary

BMI and Calorie Glossary

Use this glossary when a health estimate asks for weight, height, activity level, calories or protein targets.

What this glossary is for

Health calculators are estimates. The terms help explain what is being estimated and where personal context can change the answer.

Key terms

BMI

Body mass index, calculated from weight and height. It is a broad screening number, not a full health assessment.

BMR

Basal metabolic rate, an estimate of energy used at rest before normal activity is added.

TDEE

Total daily energy expenditure. It estimates daily calories after activity level is included.

Maintenance calories

An estimate of calories needed to keep body weight roughly stable.

Calorie deficit

Eating fewer calories than estimated expenditure. It is an estimate and can be affected by tracking error and body changes.

Activity level

A multiplier used to estimate daily energy needs from movement and exercise.

Protein target

A planning estimate for daily protein, often based on body weight and goal.

How to use the terms

Read the definition first, then open the calculator that uses the same term. Change one input at a time so you can see which number drives the result.

Main related calculator

The first tool below is the most directly related calculator for this glossary. The remaining links stay within the same topic so the page does not send visitors into unrelated tools.