Free Calorie Deficit Calculator

Find Your Daily Calorie Target

Calculate your maintenance calories and the right deficit to lose weight at a safe, sustainable pace — backed by the Mifflin-St Jeor formula.

Mifflin-St Jeor Formula
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Instant Results
4 Goal Presets
3,500kcal ≈ 1 lb Fat
< 60sTo Get Results
6Activity Levels
Calorie Deficit Calculator
Mifflin-St Jeor + Activity Multiplier
Gender

Your Results

Maintenance Cal.
Target Calories
Est. Weekly Change
Fill in your details and press calculate.
Note: This calculator provides estimates based on the Mifflin-St Jeor equation and standard activity multipliers. Individual metabolism varies — it's for education and convenience only and cannot replace advice from a doctor or registered dietitian.
How It Works

Three Steps to Your Daily Calorie Target

No food diary required up front — just a few personal details and a goal.

01

Enter Your Details

Choose your unit system and gender, then enter your age, height, weight, and how active you are day to day.

02

We Calculate Your TDEE

We estimate your Basal Metabolic Rate (BMR) and multiply it by your activity level to find your maintenance calories.

03

Pick a Goal, Get Your Target

Select a goal — lose, maintain, or gain — and instantly see your daily calorie target and expected weekly change.

The Basics

What Is a Calorie Deficit?

A calorie deficit happens when you consistently eat fewer calories than your body burns in a day. Your body responds by drawing on stored energy — mostly fat — to make up the difference, which results in weight loss over time.

The relationship is governed by simple energy balance: calories in versus calories out. One pound of body fat stores roughly 3,500 kcal of energy (about 7,700 kcal per kilogram), so a consistent daily deficit translates fairly predictably into a weekly rate of fat loss.

Why It Matters

Why Getting the Deficit Right Matters

1

Too Small Stalls Progress

A deficit that's too modest can be wiped out by normal day-to-day variation in intake or activity, making weight loss feel impossibly slow.

2

Too Large Backfires

An overly aggressive deficit increases the risk of muscle loss, fatigue, nutrient gaps, and the kind of metabolic slowdown that leads to rebound weight gain.

3

The Right Size Is Sustainable

A moderate, well-matched deficit is easier to stick to for months — and consistency, not intensity, is what actually drives long-term fat loss.

The Formula

How We Calculate Your Calorie Target

We use the Mifflin-St Jeor equation — widely regarded as the most accurate BMR formula for the general population — then layer on your activity level and goal.

Men

BMR (Male)

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

Mifflin-St Jeor Equation
Women

BMR (Female)

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Mifflin-St Jeor Equation

From BMR to Target Calories

BMR is multiplied by an activity factor to get your TDEE (Total Daily Energy Expenditure), then adjusted by your goal percentage to get your final target.

Swipe to see all columns →

Activity LevelMultiplierDescription
Sedentary× 1.2Little or no exercise, desk job
Lightly Active× 1.375Light exercise or sports 1–3 days/week
Moderately Active× 1.465Moderate exercise or sports 3–5 days/week
Active× 1.55Hard exercise or sports 6–7 days/week
Very Active× 1.725Hard daily exercise plus physical activity
Extra Active× 1.9Very hard exercise combined with a physical job
Choosing a Pace

Choosing a Safe, Sustainable Deficit

Bigger isn't always better — the right deficit size depends on how much you have to lose and how sustainable the plan needs to be.

Deficit Pace% Below TDEEEst. Weekly Loss
Mild−10 to −15%~0.3–0.5 lb
Moderate−20%~1 lb
Aggressive−25%~1.5–2 lb
Extreme−25%+Not recommended

What Makes a Deficit Backfire

Cutting calories too far below BMR for an extended period
Skipping protein, which accelerates muscle loss
No strength training to signal "keep this muscle"
Chronic under-eating, which slows metabolism over time
All-or-nothing thinking that leads to rebound overeating

What Makes a Deficit Sustainable

A moderate 15–25% deficit matched to your goal
Adequate protein to preserve lean mass
Regular resistance training during the deficit
Periodic diet breaks to manage hunger and adherence
Recalculating your target every 10–15 lbs lost
Energy Balance

Calories In vs. Calories Out

Your "calories out" side isn't just exercise — it's made up of several components, and understanding them helps explain why two people can eat the same and lose weight at different rates.

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What Makes Up TDEE

BMR (≈60–75%) — energy spent on basic survival: breathing, circulation, cell repair
NEAT (≈15–30%) — non-exercise movement like walking, fidgeting, and standing
TEF (≈8–10%) — thermic effect of food, the energy used to digest what you eat
Exercise (≈5–10%) — calories burned during intentional workouts
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Ways to Create the Deficit

Calorie counting — most precise, tracks intake directly against your target
Portion control — simpler and less precise, relies on consistent plate sizes
Intermittent fasting — restricts the eating window, which often reduces intake naturally
Any method works as long as it consistently puts you below your TDEE

For the BMR and TDEE side of this equation, you can also try our Metabolic Age & BMR Calculator to see how your metabolism compares to others your age, or check out our macro calculator to split your target calories into protein, carbs, and fat.

Taking Action

8 Tips for a Sustainable Calorie Deficit

Long-term fat loss comes from a handful of consistent habits, not extreme short-term measures.

1

Choose a Moderate Deficit

Aim for roughly 15–25% below maintenance — large enough to see results, small enough to stick with and preserve muscle.

2

Prioritize Protein

Around 0.7–1g of protein per pound of bodyweight helps preserve lean mass and keeps you fuller for longer in a deficit.

3

Strength Train Regularly

Resistance training signals your body to hold onto muscle even as you lose fat, improving your body composition.

4

Walk More (NEAT)

Daily steps and incidental movement burn meaningful calories without adding training fatigue or hunger spikes.

5

Sleep 7–9 Hours

Poor sleep raises hunger hormones and makes adherence to a deficit noticeably harder, even with a solid plan.

6

Avoid Liquid Calories

Sugary drinks and alcohol add up fast and rarely leave you feeling satisfied, eating into your deficit unnoticed.

7

Track Consistently

Logging food — even loosely — keeps your actual intake honest against your calculated target.

+

Expect Plateaus

Weight loss isn't linear. As you lose weight your TDEE drops too, so plan to recalculate and adjust every few weeks.

FAQ

Common Questions

Everything you need to know about calculating and managing your calorie deficit.

For most people, a moderate deficit of 15–25% below maintenance (roughly 300–750 calories per day) is the sweet spot — enough to lose fat steadily while staying sustainable and protecting muscle mass.
Common causes include underestimating portions, water retention masking fat loss, not recalculating your target as you lose weight, or a deficit that's too small to outweigh day-to-day variation. Tracking consistently for 2–3 weeks usually reveals the real trend.
It depends on your maintenance calories. For some larger individuals it may fall within a safe, moderate range; for others it could push intake dangerously low. As a rule of thumb, most adults shouldn't eat below about 1,200 (women) or 1,500 (men) calories a day without medical supervision.
Yes. As your body weight drops, your BMR and TDEE drop with it. Recalculating every 10–15 lbs lost (or every few weeks) keeps your target accurate and helps you avoid unexplained plateaus.
A diet break is a planned 1–2 week period of eating at maintenance during a longer cut. It helps with hunger, hormone levels, and mental fatigue, making it easier to stay consistent over months of dieting.
Not reliably. Very large deficits often lead to muscle loss, fatigue, and poor adherence, which frequently causes people to quit or rebound — usually resulting in slower progress overall than a moderate, sustainable deficit.
No — this calculator estimates calorie needs based on body weight, activity, and goal, not body composition changes. Combining a moderate deficit with strength training and adequate protein gives you the best chance of preserving (or even slightly building) muscle while losing fat.