Net Calories Calculator — Calories In vs Calories Out
Compare the calories you eat against the calories you burn to see your daily energy balance, weekly surplus or deficit, and the weight change it implies.
How it works
Net = calories in − (maintenance + exercise) · Weekly = net × 7 · Weight change ≈ weekly ÷ 3,500 lb
Body weight follows energy balance: eat more than you burn and the surplus is stored, mostly as fat; eat less and the body draws on reserves. The rule of thumb is that roughly 3,500 kcal maps to one pound of body-fat energy, so a steady 500 kcal daily deficit trends toward about a pound a week. The estimate is a guide, not a guarantee — water shifts, glycogen and metabolic adaptation make real-world scales noisier than the arithmetic.
Worked example
You eat 2,200 kcal, your maintenance burn is 2,000 kcal and a workout adds 300 kcal, so calories out total 2,300. Net = 2,200 − 2,300 = −100 kcal per day, a small deficit of 700 kcal per week ≈ 0.20 lb lost.
Frequently asked questions
Is the 3,500 calories per pound rule exact?
No. It is a useful average for body fat, but real weight change also involves water, muscle and metabolic adaptation, so short-term scale readings often diverge from the calculation. It works best as a trend over several weeks.
Where do I get my maintenance number?
Use a TDEE calculator, which combines your basal metabolic rate with an activity factor. If you already track intake and your weight is stable, your average daily calories are a good estimate of maintenance.
Should I count exercise calories separately?
Only if your maintenance figure does not already include them. Many TDEE estimates bake in typical activity, so adding a big workout number on top can double-count. Enter only exercise beyond your usual day.
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Educational estimate using standard published formulas — not medical, dietary or nutritional advice. Individual needs vary with health status, medication and activity; consult a qualified clinician or dietitian before making changes.