Health calculators

Weight Loss Calorie Calculator

Updated Jul 9, 2026 By Jehan Wadia
Rate Formulas Medical disclaimer
Your Details
Ages 15–80
Sex
Affects BMR & safe calorie floor.
Height
Feet
Inches
lbs
lbs
Activity Level
Pick the tier that best matches a typical week.

Your Personalized Calorie Plan

Maintenance Calories
—
Recommended Daily Intake
—
Daily Calorie Deficit
—
Est. Weight Loss Rate
—
Deficit Aggressiveness
Projected Weight Loss Timeline
Macronutrient Breakdown
Daily macro targets by diet profile, based on your recommended daily intake.
Diet Profile Carbs Protein Fat
Suggested Daily Meal Distribution
A suggested split of your recommended intake — not a prescription.
Suggested calorie distribution across four meal slots.
MealShareCalories
Zigzag Schedule 1: High/Low Split
Two higher-calorie days and five lower-calorie days; weekly total preserved.
Varying daily intake may help prevent metabolic adaptation and support long-term progress.
Zigzag Schedule 2: Gradual Variation
A wave that ramps up mid-week then tapers; same weekly total.
Gradual day-to-day variation adds flexibility while keeping the same weekly energy balance.
Step-by-Step Solution

Introduction

This weight loss calorie calculator shows you how many calories to eat each day to reach your goal weight by your target date. It uses your age, sex, height, weight, and activity level to find how many calories your body burns. Then it builds a plan that puts you in a safe calorie deficit so you lose weight at a steady pace.

Unlike simple calculators that use a flat "3,500 calories per pound" rule, this tool uses an adaptive body weight model. That means it accounts for how your metabolism slows down as you lose weight, giving you a more accurate and realistic plan. It also sets a safe calorie floor — 1,500 kcal per day for men and 1,200 kcal per day for women — so your intake never drops too low.

Along with your daily calorie target, you get a full macronutrient breakdown, a suggested meal split, two zigzag calorie schedules to prevent plateaus, and a projected weight loss chart. Enter your details below, press Calculate, and get your personalized plan in seconds.

How to Use Our Weight Loss Calorie Calculator

Enter your body stats, goal weight, and timeline below. The calculator will tell you how many calories to eat each day to reach your goal, plus a meal plan, macro targets, and a weight loss chart.

Unit System: Pick US/Imperial or Metric at the top. This changes all weight and height fields to match your preferred units.

Age: Enter your current age in years. This must be between 15 and 80. Your age affects how many calories your body burns at rest.

Sex: Select Male or Female. This changes your base calorie burn and sets the safe minimum calorie floor for your plan.

Height: Enter your height in feet and inches, or in centimeters if you chose Metric. Your height helps calculate how many calories your body needs each day.

Current Weight: Enter how much you weigh right now in pounds or kilograms.

Goal Weight: Enter the weight you want to reach. This must be different from your current weight. If you are unsure what to aim for, try our ideal body weight calculator for a research-based starting point.

Start Date: Pick the date you plan to begin your weight loss journey.

Target Date: Pick the date you want to reach your goal weight by. This must be after your start date. If your timeline is too short and would drop calories below a safe level, the calculator will extend it for you.

Activity Level: Choose the option that best fits your typical week. This ranges from sedentary (no exercise) to extra active (hard training twice a day). A higher activity level means your body burns more calories. If you want to estimate how many calories a specific workout burns, use our calories burned calculator.

BMR Formula (Advanced): Click "Advanced Settings" to pick a different formula for your base calorie burn. Mifflin-St Jeor works best for most people. Choose Katch-McArdle only if you know your body fat percentage.

Body Fat Percentage (Advanced): This field appears only when you select the Katch-McArdle formula. Enter your body fat percentage between 1 and 70.

Display Results In (Advanced): Choose whether to show your results in calories (kcal) or kilojoules (kJ).

When you are ready, press the Calculate button to see your results. Press Reset at any time to clear your entries and start over.

How This Weight Loss Calorie Calculator Works

This calculator figures out how many calories you need to eat each day to reach your goal weight by your target date. It uses your age, height, current weight, sex, and activity level to find your Total Daily Energy Expenditure (TDEE) — the number of calories your body burns in a normal day. For a standalone look at this number, try our TDEE calculator. Then it calculates how much less you need to eat to lose weight at a steady pace.

What Is a Calorie Deficit?

A calorie deficit means eating fewer calories than your body uses. When you do this, your body turns to stored fat for energy, and you lose weight. The bigger the deficit, the faster you lose weight — but going too low can be unsafe. This calculator never drops below 1,500 calories per day for men or 1,200 calories per day for women, which are widely accepted safe minimums. You can explore deficit strategies in more detail with our calorie deficit calculator.

Your BMR and Why It Matters

Your Basal Metabolic Rate (BMR) is the number of calories your body needs just to stay alive — breathing, pumping blood, and keeping your organs running. Even if you stayed in bed all day, your body would still burn this amount. You can find this number on its own with our BMR calculator. The calculator multiplies your BMR by an activity factor to estimate your true daily burn. You can choose from three proven BMR formulas: Mifflin-St Jeor (best for most people), Harris-Benedict, or Katch-McArdle (best if you know your body fat percentage).

Dynamic Weight Projection

Most simple calculators treat weight loss as a straight line. This one does not. It uses a model based on research by Dr. Kevin Hall at the National Institutes of Health. As you lose weight, your body burns fewer calories. This calculator accounts for that change week by week, giving you a more realistic timeline and a more accurate daily calorie target. For a broader look at your weight loss trajectory, see our weight loss calculator.

Zigzag Calorie Cycling

The calculator also gives you two zigzag schedules. Instead of eating the same amount every day, you eat more on some days and less on others. The weekly total stays the same, so you still lose weight at the same rate. Many people find this easier to stick with because it allows for bigger meals on certain days. If you are considering structured eating windows alongside calorie cycling, our fasting calculator can help you plan those periods.

Macronutrient Breakdown

Calories are not the whole story. The calculator splits your daily intake into carbs, protein, and fat across four common diet styles: balanced, low-fat, low-carb, and high-protein. For a deeper dive into custom macro splits, use our macro calculator. Protein helps you keep muscle while you lose fat. Picking the right balance can make your diet feel more satisfying and easier to follow. If you are interested in a very-low-carb approach, our keto calculator can tailor those numbers for you.

Tips for Safe Weight Loss

  • Aim to lose no more than 1–2 pounds (0.5–1 kg) per week for lasting results.
  • Never eat below the safe calorie floor without a doctor's guidance.
  • Drink plenty of water, get enough sleep, and include some physical activity.
  • Track your BMI and waist-to-hip ratio alongside the scale to get a fuller picture of your progress.
  • Use this calculator as a starting point — not a medical plan. Talk to a healthcare provider before making big changes to your diet.

Formulas used

Mifflin-St Jeor BMR
\text{BMR} = 10W + 6.25H - 5A + S \quad (S = +5 \text{ male},\; -161 \text{ female})
Revised Harris-Benedict BMR (male)
\text{BMR} = 13.397W + 4.799H - 5.677A + 88.362
Revised Harris-Benedict BMR (female)
\text{BMR} = 9.247W + 3.098H - 4.330A + 447.593
Katch-McArdle BMR
\text{BMR} = 370 + 21.6 \times \text{LBM}, \quad \text{LBM} = W\!\left(1 - \frac{\text{BF\%}}{100}\right)
Total Daily Energy Expenditure
\text{TDEE} = \text{BMR} \times \text{PAL}
Hall Dynamic Weight-Change Model
r = \frac{10.4}{F_{\!M}},\quad \rho = \frac{9440 + 1800\,r}{1 + r},\quad \Delta W = \frac{\text{Intake} - \text{TDEE}}{\rho}

Frequently asked questions

How many calories should I eat a day to lose weight?

It depends on your body and your goal. Most people lose weight safely by eating 500 calories less than their body burns each day. This usually leads to about 1 pound of weight loss per week. Enter your details into the calculator above to get your exact number.

What is the safe minimum number of calories per day?

For men, the safe floor is 1,500 calories per day. For women, it is 1,200 calories per day. Eating less than this can cause muscle loss, nutrient gaps, and other health problems. This calculator will never give you a number below that floor.

Why did the calculator change my target date?

Your original timeline would have required eating below the safe calorie floor. Instead of giving you an unsafe plan, the calculator caps your intake at the safe minimum and extends your timeline so you still reach your goal weight without risking your health.

What is the best BMR formula to use?

Mifflin-St Jeor is the most accurate for most people and is selected by default. Use Katch-McArdle only if you know your body fat percentage. Harris-Benedict is an older formula that still works well but may slightly overestimate calories for some people.

How do I pick the right activity level?

Think about what a normal week looks like for you. If you sit most of the day and do not exercise, pick Sedentary. If you walk or do light workouts a few times a week, pick Lightly Active or Moderately Active. Only pick the higher levels if you do hard exercise most days. When in doubt, pick a lower level — it is safer to underestimate.

What is a zigzag calorie schedule?

A zigzag schedule means you eat different amounts on different days of the week. Some days are higher, some are lower, but the weekly total stays the same. This can help prevent your body from adapting to a fixed intake and may make your diet easier to follow.

Is losing 2 pounds a week safe?

For most people, losing 1 to 2 pounds per week is considered safe. Losing more than 2 pounds per week for a long time can cause muscle loss, nutrient problems, and other health issues. If the calculator shows a very aggressive deficit, try extending your target date.

Why does the calculator show different results than a simple calorie formula?

Simple formulas assume you burn the same calories every day no matter how much weight you lose. This calculator uses an adaptive model that accounts for your metabolism slowing down as you get lighter. That gives you a more realistic calorie target and timeline.

Which macronutrient profile should I choose?

The Balanced profile (50% carbs, 20% protein, 30% fat) works well for most people. Choose High-Protein if you want to keep more muscle while losing fat. Choose Low-Carb if you feel better eating fewer carbs and more fat. There is no single best split — pick the one you can stick with.

Can I use this calculator to gain weight?

Yes. If you set a goal weight that is higher than your current weight, the calculator will show you how many calories to eat for weight gain. It will give you a caloric surplus instead of a deficit.

How accurate is the projected weight loss chart?

The chart gives a good estimate based on science, but real results will vary. Water retention, muscle gain, stress, sleep, and hormones can all affect your actual weight day to day. Use the chart as a guide, not a guarantee.

What does the deficit aggressiveness meter mean?

It shows how large your daily calorie deficit is. Mild (under 250 kcal) is slow and easy. Moderate (250–500 kcal) is the standard recommended range. Aggressive (501–750 kcal) is faster but harder to maintain. Very Aggressive (over 750 kcal) is not recommended without medical supervision.

Do I need to know my body fat percentage to use this calculator?

No. Body fat percentage is only needed if you pick the Katch-McArdle formula in Advanced Settings. The default Mifflin-St Jeor formula does not require it and works well for most people.

Should I eat the same calories every day?

You do not have to. The calculator gives you a flat daily target and two zigzag schedules. All three options lead to the same weekly calorie total. Some people prefer eating the same amount every day for simplicity. Others like varying their intake to feel less restricted.

What happens if I hit a weight loss plateau?

Plateaus are normal. As you lose weight, your body burns fewer calories. You can break through by slightly lowering your intake, increasing your activity, or trying zigzag calorie cycling. Recalculate with your new current weight to get an updated plan.

Does this calculator account for exercise calories?

Yes, through the activity level you select. A higher activity level means the calculator assumes you burn more calories each day. You do not need to add exercise calories separately.

Can teenagers use this calculator?

The calculator accepts ages 15 and older. However, teens are still growing and have different nutritional needs. If you are under 18, talk to a doctor or dietitian before starting any calorie-restricted diet.

What is the difference between calories and kilojoules?

They are two units that measure the same thing — energy in food. 1 calorie (kcal) equals 4.184 kilojoules (kJ). Most countries use calories, but some use kilojoules. You can switch between them in Advanced Settings.

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