---
title: "Calorie Deficit & TDEE Calculator | BQ Calculator"
canonical: "https://calculator.bqtools.com/calorie-deficit-calculator/"
description: "Estimate BMR, TDEE, calorie deficit, target calories and illustrative macros using the Mifflin–St Jeor equation with US and metric units."
---

# Calorie Deficit & TDEE Calculator

Estimate BMR, maintenance calories and a planning calorie target using the Mifflin–St Jeor equation and your selected activity level.

BQ Calculator · https://calculator.bqtools.com/calorie-deficit-calculator/

## Inputs

Share links contain only the values needed to recreate this calculation.

## Estimated daily targets

Macro split is an illustrative planning estimate, not an individualized prescription.

## What this calculator estimates

This calculator estimates basal metabolic rate (BMR), applies an activity factor to estimate total daily energy expenditure (TDEE), then subtracts the selected planning deficit. These are general estimates, not direct metabolic measurements.

## Mifflin–St Jeor formula

```text
Male equation: BMR = 10W + 6.25H - 5A + 5 Female equation: BMR = 10W + 6.25H - 5A - 161
```

W is body weight in kilograms, H is height in centimeters, and A is age in years. The two selector options correspond to the constants required by the published equation.

## TDEE and calorie target

```text
TDEE = BMR × activityFactor targetCalories = TDEE - dailyDeficit
```

The activity multipliers used here are 1.20 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, and 1.90 extra active. The goal options use approximate daily deficits of 250, 500, 750, or 1,000 kcal.

## Illustrative macro breakdown

The result panel also divides the estimated calorie target into 30% protein, 40% carbohydrate and 30% fat. Protein and carbohydrate use 4 kcal per gram; fat uses 9 kcal per gram.

## Safety and limitations

This tool provides general estimates only. It does not diagnose, measure metabolism exactly, or provide personalized medical or nutrition advice. Energy needs vary substantially between people, and weight changes are not guaranteed by a simple calorie calculation.

## Frequently asked questions

### What does TDEE mean?

TDEE means total daily energy expenditure. It is an estimate of the calories your body may use in a day after applying an activity multiplier to an estimated basal metabolic rate.

### How accurate is the Mifflin–St Jeor equation?

It is an estimation equation, not a direct measurement. Individual metabolism, body composition, health conditions and real activity can make actual energy needs differ.

### Why do the sex options say “used by equation”?

The Mifflin–St Jeor equation uses different constants for its male and female versions. The selector identifies which published equation constant is being applied.

### Are the macro targets personalized?

No. The displayed 30% protein, 40% carbohydrate and 30% fat split is an illustrative planning breakdown of the estimated calorie target, not an individualized nutrition prescription.

### Should I use a very large calorie deficit?

Aggressive deficits can be inappropriate for many people. The calculator flags unusually low estimated calorie targets and should not replace guidance from a qualified clinician or dietitian.

### Related calculators

All calculation inputs stay local to this browser.

## Machine-readable resources

- Calculator registry: https://calculator.bqtools.com/calculators.json
- Site index: https://calculator.bqtools.com/llms.txt
- Full agent text: https://calculator.bqtools.com/llms-full.txt
- Agent discovery index: https://calculator.bqtools.com/agent-index.json