Calories to Lose Weight Calculator

Unit system *

Gender *

Age (years) *

Weight (kg) *

Height (cm) *

Goal weight (kg) (optional)

Weight (lb) *

Height (ft) *

Height (in)

Goal weight (lb) (optional)

Activity level *

Includes training and daily movement.

BMR formula *

Katch is best with a reliable body-fat estimate.

Body fat (%) (optional)

Used only for Katch–McArdle.

Deficit method *

Rate-based uses 7,700 kcal per kg.

Loss rate *

Typical range: 0.25–1.00 kg/week.

Deficit percentage *

Common range: 10–25% of maintenance.

Protein (g/kg) *

Higher protein supports muscle retention.

Fat (g/kg) *

Supports hormones and satiety.

Example data table

Profile	Inputs	Outputs (approx.)
Moderate activity	Male, 30y, 78 kg, 175 cm, 0.5 kg/week	BMR 1,724 kcal, TDEE 2,672 kcal, Target ~2,122 kcal
Light activity	Female, 28y, 62 kg, 165 cm, 20% deficit	BMR 1,353 kcal, TDEE 1,860 kcal, Target ~1,488 kcal
Very active	Male, 40y, 90 kg, 180 cm, 0.75 kg/week	BMR 1,814 kcal, TDEE 3,129 kcal, Target ~2,304 kcal

Formula used

BMR (Mifflin–St Jeor): Men = 10W + 6.25H − 5A + 5, Women = 10W + 6.25H − 5A − 161
BMR (Harris–Benedict revised): Uses age, weight, and height constants for men and women.
BMR (Katch–McArdle): 370 + 21.6 × LBM, where LBM = W × (1 − bodyFat%)
Maintenance (TDEE): TDEE = BMR × Activity factor
Rate-based deficit: Weekly deficit = 7,700 × kg/week, daily deficit = weekly ÷ 7
Percent-based deficit: Daily deficit = TDEE × deficit%
Target calories: Target = TDEE − Daily deficit
Macros: Protein kcal = g×4, Carbs kcal = g×4, Fat kcal = g×9

These estimates are for general information. If you have a medical condition, consult a qualified professional for personalized targets.

How to use this calculator

Select your unit system and enter age, height, and weight.
Pick an activity level that matches your weekly routine.
Choose a BMR formula; add body fat if using Katch.
Select a deficit method: weekly loss rate or percentage.
Adjust protein and fat settings for your preference.
Click Calculate to view target calories and macros.
Use CSV or PDF buttons to save your report.

Article: Calories for Weight Loss Planning

1) Why calories matter for fat loss

Body weight changes when energy intake and energy use differ over time. This calculator estimates your maintenance calories, then subtracts a controlled deficit. A consistent deficit is the practical driver of fat loss, while protein and fat targets help keep the plan sustainable.

2) Basal calories and maintenance calories

Basal Metabolic Rate (BMR) is the calories your body uses at rest for breathing, circulation, and basic function. Maintenance calories (often called TDEE) adds activity on top of BMR. Here, maintenance is calculated as TDEE = BMR × activity factor.

3) Activity factors used in this tool

To reflect lifestyle differences, the calculator uses common multipliers: sedentary 1.20, light 1.375, moderate 1.55, very active 1.725, and extra active 1.90. Selecting the closest match improves the maintenance estimate.

4) BMR formulas and when to use them

Mifflin–St Jeor is widely used for general estimating because it relies on age, height, weight, and sex. Harris–Benedict (revised) is another classic equation with different constants. Katch–McArdle uses lean body mass, so it benefits from a realistic body‑fat estimate.

5) Two deficit methods: rate or percent

Rate‑based dieting chooses a weekly loss rate and converts it into calories. The calculator uses 7,700 kcal per kilogram as an energy equivalent to estimate the needed deficit. Percent‑based dieting sets the deficit as a percentage of maintenance, often around 10–25%.

6) Protein, fat, and carbs as daily targets

After your calorie target is set, the tool builds macros. Protein is calculated from your chosen g/kg value, and fat is also set in g/kg. Remaining calories are assigned to carbs. This approach keeps the math simple while staying adjustable.

7) Safety checks and realistic pacing

Aggressive deficits can reduce diet quality and increase fatigue. For general guidance, the calculator applies common minimum daily calories and shows notes when targets drop below basal needs. If the plan feels overly restrictive, reduce the loss rate or choose a smaller percent deficit.

8) How to validate your result in real life

Use the target for 10–14 days while tracking intake and morning scale trends. If weight is stable, reduce calories slightly or increase activity. If loss is too fast or hunger is extreme, add calories back. Small weekly adjustments usually outperform big swings.

FAQs

1) What is the difference between BMR and TDEE?

BMR estimates calories your body needs at rest. TDEE adds activity by multiplying BMR with an activity factor. TDEE is your approximate maintenance intake.

2) Why does the calculator use 7,700 kcal per kilogram?

It is a commonly used energy equivalent for estimating fat loss. Real results vary because water, glycogen, and metabolic adaptation can change scale weight week to week.

3) Should I pick rate-based or percent-based deficit?

Rate-based is intuitive if you have a weekly goal. Percent-based is useful if you want a consistent percentage cut from maintenance. Both methods can work when your plan is sustainable.

4) Do I need body-fat percentage for accurate results?

Not required. Body-fat is only used for the Katch–McArdle option. If you do not know it, Mifflin–St Jeor is a solid default for most people.

5) Why are protein and fat set in g/kg?

Using grams per kilogram scales targets with body size. It also makes the plan easy to personalize while keeping calories consistent. Carbs then fill the remaining calories.

6) What if my target calories feel too low?

Choose a smaller deficit or slower weekly loss rate. You can also reassess activity selection. Consistency and adherence matter more than pushing the lowest possible calorie number.

7) How often should I update my numbers?

Recalculate after notable weight changes, such as every 2–4 weeks, or when your activity routine changes. As body weight decreases, maintenance calories often decline gradually.