Healthy food plate, scale and downward calorie arrow for the free calorie deficit calculator
A calorie deficit means eating fewer calories than your body burns each day.

Calorie Deficit Calculator

Direct answer: A calorie deficit is when you eat fewer calories than your Total Daily Energy Expenditure (TDEE). A daily deficit of 500 calories typically leads to about 0.45 kg (1 lb) of weight loss per week.







Your daily calorie target: 2133 calories/day

BMR: 1699 calories/day · TDEE: 2633 calories/day · Deficit: 500 calories/day

Estimated loss: about 0.45 kg per week

How the calculation works

Step 1: BMR (Mifflin-St Jeor equation) — Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. Women: the same formula with −161 instead of +5.
Step 2: TDEE = BMR × activity factor.
Step 3: Target calories = TDEE − deficit, then raised to a safe minimum when lower (1,500 calories/day for men, 1,200 for women).
Step 4: Weekly loss estimate uses 3,500 calories ≈ 0.45 kg (1 lb).

Calorie deficit formula worked step by step
Figure 1 — The calculation in four steps: BMR from the Mifflin-St Jeor equation, TDEE from BMR × activity factor, target calories from TDEE − deficit, and weekly loss from 3,500 calories ≈ 0.45 kg. — averagecalculatoronline.com

Deficit size and expected weekly loss

250 calories/day → about 0.23 kg per week.
500 calories/day → about 0.45 kg per week.
750 calories/day → about 0.68 kg per week.
1,000 calories/day → about 0.91 kg per week.

Weekly weight loss by daily deficit size
Figure 2 — Bigger deficit, faster loss: 250 calories/day → about 0.23 kg per week, up to 1,000 calories/day → about 0.91 kg per week. — averagecalculatoronline.com

Worked examples

Example 1: Male, 30 years, 175 cm, 75 kg, moderately active. BMR = 10 × 75 + 6.25 × 175 − 5 × 30 + 5 = 1,698.75. TDEE = 1,698.75 × 1.55 = 2,633 calories/day. With a 500-calorie deficit, the daily target = 2,133 calories, and estimated loss is about 0.45 kg per week.

Example 2: Female, 28 years, 165 cm, 60 kg, lightly active. BMR = 1,330.25. TDEE = 1,330.25 × 1.375 = 1,829 calories/day. With a 500-calorie deficit, the daily target = 1,329 calories.

Daily calorie targets from worked examples
Figure 3 — Two worked targets: a moderately active man (2,133 calories/day) and a lightly active woman (1,329 calories/day), both with a 500-calorie deficit. — averagecalculatoronline.com

What to watch out for

A deficit above 1,000 calories a day is aggressive and hard to sustain; very low intakes are commonly discouraged (often cited minimums are around 1,200 calories for women and 1,500 for men) unless supervised by a clinician. Weight loss also slows over time as the body adapts, so recalculate your target every few weeks.

Activity factor ladder for TDEE
Figure 4 — Activity level sets the TDEE multiplier: recalculate your target when your routine changes, and stay above the safe minimums. — averagecalculatoronline.com

FAQs

What is a calorie deficit?

A calorie deficit is eating fewer calories than your TDEE (the calories your body burns daily). The shortfall forces the body to use stored energy, which leads to weight loss.

How much calorie deficit is safe?

A deficit of 250–750 calories per day is the most commonly recommended range for steady, sustainable loss. Deficits above 1,000 calories a day are aggressive and best discussed with a clinician.

How fast will I lose weight in a calorie deficit?

A 500-calorie daily deficit typically produces about 0.45 kg (1 lb) per week, since 3,500 calories ≈ 0.45 kg. Actual results vary with activity, diet, and metabolic adaptation.

Does this calculator account for exercise?

Yes, through the activity level you select. If your exercise routine changes, update the activity level and recalculate.

Disclaimer: This tool provides general information only, not medical advice. Consult a clinician before starting a weight-loss plan, especially with a medical condition.

Related calculators: Calorie Calculator · BMI Calculator · TDEE Calculator

Last updated: November 1, 2026.