Use this calorie deficit calculator guide for weight loss. Learn your TDEE, choose the right deficit size, and reach safe, sustainable fat loss targets.
Frequently Asked Questions
How do I calculate my calorie deficit for weight loss?
First, calculate your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation multiplied by your activity factor. Then subtract 300–500 calories from that number to create a safe deficit that produces roughly 0.5–1 lb of fat loss per week.
How big should my calorie deficit be?
A deficit of 300–500 calories per day is recommended for most people. This rate produces 0.5–1 lb of fat loss per week without triggering muscle loss or metabolic adaptation. Deficits above 1,000 calories per day are generally unsafe without medical supervision.
Is it safe to eat 1,000 calories a day to lose weight?
No. Healthcare guidelines recommend a minimum of 1,200 calories per day for women and 1,500 for men. Eating below these thresholds can cause muscle loss, nutrient deficiencies, and metabolic slowdown. Always build your deficit from your TDEE, not an arbitrary floor.
How many calories equal 1 lb per week of weight loss?
Roughly a 500-calorie daily deficit produces approximately 1 lb of fat loss per week, based on the 3,500-calorie estimate for one pound of fat. In practice, the rate slows as you lose weight and your body adapts, so treat it as a planning estimate, not a guarantee.
Why am I not losing weight in a calorie deficit?
Common reasons include underestimating portions, forgetting liquid calories, NEAT downregulation, and metabolic adaptation from prolonged dieting. Try logging everything on a food scale for one full week — the data almost always pinpoints the gap.