🔥 Health · Calorie Deficit

How to Calculate a
Calorie Deficit

Find your TDEE, set your target, and calculate exactly how many calories to eat for safe and steady weight loss.

The Calorie Deficit Formula

Deficit = TDEE – Target Calories
3,500 calories ≈ 0.45 kg (1 lb) of fat
TDEE
Total Daily Energy Expenditure — how many calories your body burns in a day
Safe Deficit
300–500 cal/day = 0.25–0.5 kg/week. Avoid deficits over 1,000 cal/day.
💡 Mifflin-St Jeor formula for BMR: Men: (10×kg) + (6.25×cm) – (5×age) + 5. Women: (10×kg) + (6.25×cm) – (5×age) – 161. Multiply by activity factor for TDEE.

Calorie Deficit Calculator

Your TDEE
0
calories/day to maintain weight
Choose your goal
Slow
–250 cal
—
Moderate
–500 cal
—
Aggressive
–750 cal
—
Target Calories
—
Loss per Week
—
Loss per Month
—
BMR (base)
—

Step-by-Step Guide

1

Calculate your BMR

Basal Metabolic Rate = calories your body burns at rest. Use Mifflin-St Jeor: Men: (10×80) + (6.25×175) – (5×30) + 5 = 1,836 kcal

2

Multiply by activity factor

TDEE = BMR × activity. Moderately active (×1.55): 1,836 × 1.55 = 2,846 kcal/day to maintain weight.

3

Subtract your deficit

Safe deficit: 300–500 kcal/day. 2,846 – 500 = 2,346 kcal/day to lose ~0.5 kg/week.

4

Track and adjust

If weight stops moving after 2–3 weeks, reduce by another 100–200 kcal. Metabolism adapts — small adjustments beat dramatic cuts.

Worked Examples

Woman, 65 kg, 30yr

BMR: ~1,444 kcal
TDEE (mod): ~2,238
–400 deficit
Eat 1,838 kcal/day

Man, 90 kg, 35yr

BMR: ~1,980 kcal
TDEE (mod): ~3,069
–500 deficit
Eat 2,569 kcal/day

Slow & steady

250 kcal/day deficit
= 1,750 kcal/week
= ~0.25 kg/week
~1 kg/month

Faster loss

750 kcal/day deficit
= 5,250 kcal/week
= ~0.75 kg/week
~3 kg/month

More Health Calculators

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BMI
Body mass index
⚖️
Maintenance Calories
TDEE in detail
🥗
Macros
Protein, carbs & fat
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Body Fat %
Fat vs muscle
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Heart Rate
Training zones
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Net Income
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Frequently Asked Questions

How many calories should I eat to lose weight? ▾
Eat 300–500 calories below your TDEE. This creates a sustainable deficit that results in 0.25–0.5 kg of fat loss per week without slowing your metabolism too much.
Is a 1,000 calorie deficit safe? ▾
A 1,000 calorie deficit is generally too aggressive for most people. It risks muscle loss, nutrient deficiencies, fatigue, and metabolic adaptation. Most experts recommend a maximum of 500–750 cal/day deficit.
Why did my weight loss stall? ▾
As you lose weight, your TDEE decreases because your body is smaller. You should recalculate your TDEE every 4–6 weeks and adjust your intake accordingly. Plateaus are normal and expected.
Should I eat back exercise calories? ▾
If you used an activity multiplier when calculating TDEE, your exercise is already factored in — don't eat it back. If you used a sedentary multiplier, eating back 50–75% of exercise calories is a reasonable approach.