Calorie Deficit Calculator

Q: What is a calorie deficit and how does it work?

A calorie deficit means eating fewer calories than you burn (TDEE). A 500 calorie/day deficit creates ~1 lb/week loss based on the 3,500 calorie-per-pound rule.

Q: How many calories should I eat to lose 1 pound per week?

A 500 calorie/day deficit creates ~1 lb/week loss. Minimum safe intake is 1,200 cal/day for women and 1,500 cal/day for men.

Q: Can I lose weight while still eating fast food?

Yes. Weight loss depends on total calorie balance. Fast food fits a deficit diet as long as portions stay within your daily calorie target.

Q: What is TDEE and how is it calculated?

TDEE is total daily calories burned including exercise. Calculated as BMR × activity factor. BMR uses the Mifflin-St Jeor equation.

Q: How do I eat in a calorie deficit at restaurants?

Choose grilled over fried, skip fries, drink water, and check calorie counts before ordering. A grilled chicken meal typically runs 450–600 calories.

Your Stats

Age

Sex

Weight

Height

ft in

Activity Level

Weekly Weight Loss Goal

Results

BMR

—

kcal/day

TDEE

—

kcal/day

Daily Target

—

kcal/day

Weekly Deficit

—

kcal/week

Goal weight (lbs)

Enter a goal weight to see estimated time.

Understanding TDEE & Calorie Deficits

Your TDEE is the number of calories you burn in a day accounting for your activity level. Creating a deficit — eating less than your TDEE — forces the body to use stored fat. A 500 kcal daily deficit produces roughly a 1 pound per week loss under standard assumptions.

Restaurant meals are notoriously high in calories relative to portion size. A single fast food combo can consume 50–80% of a moderate TDEE. Using the calorie tracker alongside this calculator helps you stay accountable when eating out.

For less calorie-dense options at chain restaurants, see our budget dining guide — cheaper items are often also lower in calories.

Calorie Deficit Calculator — FAQs

Common questions about TDEE, BMR, and using a calorie deficit for weight management.

What is a calorie deficit and how does it work?

A calorie deficit means consuming fewer calories than your body burns in a day (your TDEE — Total Daily Energy Expenditure). Since 1 pound of fat contains roughly 3,500 calories, a daily deficit of 500 calories creates a theoretical loss of about 1 pound per week. This calculator computes your personal TDEE using the Mifflin-St Jeor equation — the most widely validated formula — then subtracts your chosen deficit.

How many calories should I eat to lose 1 pound per week?

To lose 1 pound per week, aim for a 500 calorie/day deficit from your TDEE. For most adults, this lands between 1,500–2,000 calories/day. The minimum recommended intake is 1,200 calories/day for women and 1,500/day for men — never go below these levels without medical supervision.

Can I lose weight while still eating fast food?

Yes — weight loss is driven by total calorie balance, not food source. You can eat fast food and lose weight as long as you stay within your calorie target. The challenge is that fast food is calorie-dense and portions are large. Use our calorie calculator to log your order and check whether it fits your daily budget.

What is TDEE and how is it calculated?

TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day, including exercise. It's calculated by multiplying your BMR (Basal Metabolic Rate) — the calories burned at rest — by an activity factor. This calculator uses the Mifflin-St Jeor equation for BMR: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5 (male) or −161 (female).

How do I eat in a calorie deficit at restaurants?

Order grilled proteins instead of fried, skip or split fries, choose water or diet drinks, ask for sauces on the side, and avoid combo upsells. Most chains publish nutrition data — check calories before you order. A grilled chicken sandwich, side salad, and water at most fast food chains is typically 450–600 calories.

Your Stats

Understanding TDEE & Calorie Deficits