Calorie Deficit Calculator
Calculate the daily calorie target and deficit you need to hit your weight loss goal — enter your current weight and weekly loss goal.
A 500 calorie/day deficit loses 1 lb/week — sustainable, measurable, and based on 70+ years of nutrition science.
3,500
Calories in one pound of fat — the basis for all calorie deficit planning
500
Daily calorie deficit needed to lose 1 lb per week
1–2lb
Safe weekly weight loss rate according to most health guidelines
The science of fat loss
What the research says about creating and maintaining a calorie deficit.
Deficit is just the math — adherence is everything
A 500-calorie deficit that you maintain is better than a 1,000-calorie deficit you abandon after 2 weeks. Hunger, social eating, and weekend variance all erode the calculated deficit. Track honestly and adjust based on real results every 2–3 weeks.
Protein protects muscle during fat loss
When in a calorie deficit, your body will burn muscle as well as fat — unless protein intake is high enough. Aim for 0.7–1g of protein per lb of bodyweight. This is the single most important dietary variable during fat loss.
The scale lies short-term
Day-to-day weight fluctuates by 2–5 lbs due to water, sodium, glycogen, and digestion. Weigh yourself under consistent conditions (morning, after bathroom) and track the weekly average trend — not the daily number. Progress shows in 2–4 week averages.
How the Calorie Deficit Calculator Works
Formula
Maintenance Calories = Body Weight (lbs) × 15
Daily Deficit = Weekly Loss Goal × 3,500 ÷ 7
Target Daily Calories = Maintenance − Daily Deficit
Weeks to Lose 10 lbs = 10 ÷ Weekly Loss GoalEnter your current weight
In pounds. Used to estimate your maintenance calorie level.
Set weekly weight loss goal
0.5–2 lbs per week. 1 lb/week is the most commonly recommended rate.
Read your daily target
Target calories per day, required daily deficit, and estimated weeks to lose 10 lbs.
This calculator uses 15 calories per pound of body weight as an approximate maintenance estimate for a sedentary to lightly active adult. If you're more active, your maintenance is higher and your actual deficit will be less than calculated.
This is a planning tool, not medical advice. For personalized nutrition guidance, consult a registered dietitian or your healthcare provider. Do not use this calculator to plan extremely low-calorie diets without professional supervision.
Frequently Asked Questions
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