How many calories should I eat to lose weight?

To lose weight, you need a calorie deficit — eating fewer calories than your TDEE (Total Daily Energy Expenditure). A deficit of 500 calories per day leads to approximately 1 lb (0.45 kg) of weight loss per week. Use our TDEE Calculator to find your maintenance calories, then subtract 300–500 for a sustainable deficit.

What is TDEE and how is it calculated?

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, including your basal metabolic rate (BMR) plus activity. It is calculated using your age, sex, height, weight, and activity level. Our TDEE calculator uses the Mifflin-St Jeor equation for accurate results.

What is a healthy BMI?

A BMI (Body Mass Index) between 18.5 and 24.9 is considered healthy for most adults. BMI below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese. Note that BMI doesn't account for muscle mass, so athletes may show higher BMI while being healthy.

How long will it take me to lose weight?

Weight loss timeline depends on your starting weight, calorie deficit, and activity level. A safe rate is 0.5–2 lbs (0.25–1 kg) per week. Use our Weight Loss Timeline Calculator to get a personalized estimate based on your current weight, goal weight, and daily calorie deficit.

What macros should I eat to lose weight?

A common macro split for weight loss is 40% protein, 30% carbohydrates, and 30% fat. Higher protein intake (0.7–1g per lb of body weight) helps preserve muscle mass during a calorie deficit. Use our Macro Calculator to get personalized targets based on your goals and body stats.

Weight Loss Calculator – Free TDEE, BMI, Calories, Macros & Timeline Tools

🔥 TDEE & Calorie Calculator

Your Total Daily Energy Expenditure (TDEE) is the foundation of any weight loss plan. We use the Mifflin-St Jeor equation — the most accurate formula available for most people.

Age (years)

Biological Sex

Weight (lbs)

Height (ft) e.g. 5.83 = 5'10"

Activity Level

BMR

—

cal/day at rest

TDEE (Maintenance)—
calories/day

Mild Deficit (-250)

—

≈ 0.5 lb/week

Moderate Deficit (-500)

—

≈ 1 lb/week

Aggressive (-750)

—

≈ 1.5 lb/week

Max Cut (-1000)

—

≈ 2 lb/week

Both Formulas Compared

❓ What is TDEE?

Your TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns each day — including exercise. Eat below this number to lose weight. The closer your deficit is to 500 cal/day, the more sustainable and muscle-preserving your results will be. Extreme deficits (>1000 cal/day) can cause muscle loss, fatigue, and metabolic slowdown.

📊 BMI Calculator

Body Mass Index gives a quick estimate of whether your weight is healthy for your height. Note: BMI doesn't measure body fat directly — athletes and muscular people may show "overweight" BMI despite being very healthy.

Weight (lbs)

Height (ft) e.g. 5.75 = 5'9"

Age

Sex

Your BMI—
kg/m²

📋 BMI Reference Table

BMI	Category	Health Risk
< 18.5	Underweight	Malnutrition risk, osteoporosis
18.5 – 24.9	Normal Weight ✓	Lowest risk range
25.0 – 29.9	Overweight	Moderate — elevated diabetes/heart risk
30.0 – 34.9	Obese (Class I)	High risk
35.0 – 39.9	Obese (Class II)	Very high risk
≥ 40.0	Obese (Class III)	Extremely high risk — seek medical guidance

📅 Weight Loss Timeline Calculator

How long will it take to reach your goal? Enter your current and goal weight plus your planned daily calorie deficit. Includes plateau modeling — because most people's progress slows after the first few weeks.

Current Weight

Goal Weight

Daily Calorie Deficit: 500 calories

Account for Plateau Effect?

Time to Goal—
weeks

Estimated Date

—

Weight to Lose

—

lbs

Avg Rate/Week

—

lbs/week

📖 The Science Behind Weight Loss Timelines

The classic rule is 3,500 calories = 1 lb of fat. So a 500 cal/day deficit should produce ~1 lb/week. In practice, early weeks often show faster loss — that's mostly water and glycogen, not fat.

Why do plateaus happen? As you lose weight, your body is lighter and burns fewer calories. It also reduces NEAT (Non-Exercise Activity Thermogenesis — fidgeting, posture, daily movement) by up to 300 cal/day. This is called adaptive thermogenesis.

The 0.5–1 lb/week rule: This pace is considered optimal for fat loss while preserving lean muscle. Faster rates (>2 lbs/week) risk muscle catabolism and nutrient deficiency.

Timeline math vs. reality: Real weight loss looks like a jagged line, not a smooth curve. Hormones, sodium intake, and menstrual cycles can shift scale weight by 2–5 lbs overnight. Focus on the 4-week trend, not daily numbers.

🥩 Macronutrient Calculator

Knowing your calories isn't enough — the right macro split maximizes fat loss while preserving muscle. Protein is the most important macro for weight loss.

Daily Calorie Target

Goal

Diet Preference

Body Weight (for protein floor)

📚 Macro Guide

Macro	Calories/gram	Primary Role	Min Daily (gen. rec.)
Protein	4 cal/g	Muscle repair, satiety, thermic effect	0.7g per lb body weight
Carbohydrates	4 cal/g	Energy, brain fuel, fiber	Depends on activity
Fat	9 cal/g	Hormones, fat-soluble vitamins	20–35% of calories

📐 Body Fat % Calculator

Uses the US Navy method — one of the most accurate field methods. You'll need a soft measuring tape. Measurements in inches or cm.

Sex

Height

Neck circumference (below larynx)

Waist circumference (at navel)

Hip circumference (women only, widest)

Body Fat %—

📊 Body Fat % Reference Ranges

Category	Men	Women
Essential Fat	2–5%	10–13%
Athlete	6–13%	14–20%
Fitness	14–17%	21–24%
Average	18–24%	25–31%
Obese	25%+	32%+

⚖️ Ideal Body Weight Calculator

Four different medical formulas — Devine, Robinson, Miller, and Hamwi — each give slightly different results. The average gives you a solid target range.

Sex

Height (ft) e.g. 5.67 = 5'8"

Current Weight (lbs or kg)

📖 Understanding Ideal Weight Formulas

All four formulas were developed between 1964 and 1983 for clinical drug dosing — not as fitness targets. They estimate a weight range based purely on height and sex, with no adjustment for age, muscle mass, or bone density.

Devine Formula (1974): Originally designed for kidney dialysis dosing. Still the most widely cited in clinical literature despite its age.

Why they diverge: Each was derived from a different patient population. The formulas can differ by 5–10 lbs for the same height — which is why averaging all four gives a more balanced estimate.

Limitation: A muscular athlete at 200 lbs and 5'10" may be "overweight" by these formulas yet perfectly healthy. Body fat % is a far better metric for fit individuals. Use the Body Fat tab for a more complete picture.

🏃 Exercise Calorie Burn Calculator

Enter your weight and duration to see calories burned for common activities. Based on MET (Metabolic Equivalent of Task) values from the Compendium of Physical Activities.

Your Weight (lbs)

Duration (minutes)

Activity	Intensity	Calories Burned

💡 Pro tip: Cardio burns calories during exercise; strength training burns calories for up to 48 hours after. Combine both for best results.

📖 How MET Values & Calorie Burn Work

This calculator uses MET (Metabolic Equivalent of Task) values from the Compendium of Physical Activities. A MET of 1 = energy burned at rest. Running at 7 mph (MET 11.5) burns 11.5× your resting rate.

The formula: Calories = MET × body weight (kg) × duration (hours). Heavier people burn more calories for the same activity — this is why weight is required.

Cardio vs. Strength: Cardio yields higher immediate calorie burn. Strength training builds muscle, which raises your resting metabolic rate permanently — burning more calories even while you sleep.

Don't eat back all exercise calories: Fitness trackers overestimate burn by 30–70%. Use exercise burn estimates as a bonus, not as justification to eat back the full number. Aim to keep your food deficit consistent regardless of exercise output.

📉 Plateau Predictor & Fix

One of the most frustrating parts of weight loss: you're doing everything right, but the scale stops moving. This is called metabolic adaptation — and it's completely normal.

Weeks on current deficit

Total weight lost so far (lbs)

Current daily calorie intake

Original body weight (lbs)

Plateau Risk Score—

🛠️ Science-Backed Plateau Breakers

1. Diet Break (1–2 weeks at maintenance) Eating at TDEE for 1–2 weeks resets leptin levels and reduces cortisol, often kicking off faster loss afterwards. (Byrne et al., 2017 — the "MATADOR" study)

2. Reverse Dieting Gradually increase calories by 50–100/week over several weeks to restore metabolic rate before cutting again.

3. Protein Reset Bump protein to 0.9–1g per lb of body weight. Higher protein has a thermic effect (burns 25–30% of its own calories during digestion).

4. Calorie Cycling Eat maintenance on hard training days, deficit on rest days. Prevents adaptive thermogenesis better than a fixed deficit.

5. Strength Training Adding or increasing resistance training preserves muscle during deficits, maintaining a higher RMR long-term.

⚠️ What NOT to do: Don't cut calories further below 1200 (women) or 1500 (men). This worsens metabolic slowdown and risks nutrient deficiencies.

📝 Weight Progress Tracker

Log your weight over time — stored locally in your browser. No account needed, no data leaves your device.

Date

Weight (lbs or kg)

Note (optional)

📖 Why Tracking Your Weight Works

Research consistently shows that people who self-monitor their weight lose significantly more than those who don't. A 2019 meta-analysis found daily weighers lost an average of 6.6 lbs more over 12 months than non-weighers.

Best time to weigh in: First thing in the morning, after using the bathroom and before eating. This minimizes daily variation from food and water weight. Use the same scale in the same spot each time.

Watch the trend, not the number: Daily weight fluctuates 1–5 lbs due to water retention, sodium, hormones, and digestion. The 7-day moving average (shown in the chart above) is your real signal — ignore day-to-day noise.

Scale anxiety is common: If daily weigh-ins cause stress, switch to 2–3 times per week. The consistency matters more than the frequency. Even weekly tracking is far better than none at all.

💧 Daily Water Intake Calculator

Hydration is one of the most overlooked factors in weight loss. Water suppresses appetite, boosts metabolism, and is essential for fat metabolism. Use this calculator to get your personalized daily target.

Body Weight (lbs)

Activity Level

Climate / Environment

Goal

Daily Target—
fl oz per day

In Liters

—

liters per day

In Cups (8 oz)

—

cups per day

Standard Bottles

—

× 16.9 oz bottles

💡 Why Hydration Accelerates Weight Loss

Water isn't just essential for survival — it directly influences fat metabolism, appetite control, and calorie burning. Even mild dehydration (1–2% body weight) measurably impairs these processes.

Metabolism boost (thermogenesis): Drinking 17 oz (500ml) of cold water increases metabolic rate by 24–30% for 30–40 minutes. A 2003 study in Journal of Clinical Endocrinology & Metabolism found this could burn an extra 50+ calories per day with consistent hydration.

Appetite suppression: A 2010 clinical trial found adults who drank 500ml before each meal lost 44% more weight over 12 weeks than non-pre-meal drinkers. Thirst is often mistaken for hunger — drinking first before snacking can cut unnecessary calories.

Fat burning requires water: Lipolysis (the process of burning fat) requires water molecules. Dehydration literally slows fat burning at the cellular level.

Signs of dehydration to watch: Dark yellow urine, headaches, fatigue, brain fog, hunger cravings, and workout performance drops — all impair your weight loss efforts. Aim for light yellow urine as your benchmark.

💪 One Rep Max (1RM) Calculator

Your One Rep Max is the maximum weight you can lift for a single repetition. Used by strength athletes and coaches to prescribe training loads. No need to max out — lift a submaximal weight and let the formula calculate your 1RM.

Weight Lifted

Reps Completed (1–10 for best accuracy)

Unit

Exercise (for context)

Training Load Table (% of estimated 1RM)

%	Weight	Rep Range	Training Zone

📖 How to Use 1RM for Weight Loss

Strength training is one of the most powerful tools for long-term weight management. Unlike cardio, it builds muscle which raises your resting metabolic rate (RMR) — meaning you burn more calories 24/7, not just during the workout.

For fat loss + muscle retention: Train at 70–85% of 1RM, 3–5 sets, 6–12 reps. This rep range optimizes hypertrophy and is the sweet spot for maintaining muscle during a calorie deficit.

Progressive overload: Aim to increase weight by 2.5–5 lbs (or add 1 rep) every 1–2 weeks. This is the primary driver of muscle growth and metabolic adaptation.

Compound lifts first: Bench press, squat, deadlift, and overhead press recruit the most muscle mass, burning the most calories and producing the greatest anabolic hormone response.

Safety note: Never attempt a true 1RM without a spotter and proper warm-up. Submaximal testing (3–5 reps) fed into this calculator is safer and accurate to within 2–5%.

⏱️ Intermittent Fasting Calculator

Intermittent fasting (IF) is a time-restricted eating pattern, not a diet. Calculate your optimal eating and fasting windows based on your schedule, then see the metabolic benefits you'll experience during your fast.

Fasting Protocol

Wake-up Time

Preferred Eating Window Start (optional)

Your Goal

Fasting Window—

Eating Window

—

Break Fast At

—

Stop Eating At

—

📅 What's Happening in Your Body (24h Timeline)

🔬 The Science of Intermittent Fasting

IF works through multiple mechanisms beyond just reducing calorie intake. Research shows significant metabolic and hormonal benefits that begin at specific hours into a fast.

Hours 0–4: Food digestion and absorption. Insulin rises, shuttling glucose to cells. Fat burning is suppressed during this window.

Hours 4–8: Insulin falls. Glucagon rises. The body begins drawing on liver glycogen for energy. Blood glucose stabilizes.

Hours 8–12: Glycogen stores depleting. Body shifts toward fat oxidation. Norepinephrine (metabolic rate hormone) begins rising. This is the fat-burning zone for most people.

Hours 12–18: Liver glycogen nearly exhausted. Fat burning is the primary energy source. Ketone production begins. Growth hormone starts rising (muscle-preserving effect).

Hours 16–24: Deep ketosis potential. Autophagy (cellular cleanup) peaks — cells recycle damaged proteins. HGH levels can rise 5× above baseline. Strong anti-inflammatory effects.

Who should be careful with IF: Pregnant/nursing women, people with history of eating disorders, type 1 diabetics, and those on insulin or blood sugar medication. Always consult your doctor before starting a fasting protocol.

🥗 Weight Loss Calculator Suite