Calorie Deficit Calculator
Every weight-loss plan comes down to the same mechanism: eat less than you burn. The only real decision is how big that gap should be. Enter your details below to see your deficit target at a few different paces.
Your details
Activity level
Pace
Maintenance (TDEE)
2279 kcal
Deficit calorie target
1710-1825 kcal
Protein target to protect muscle while cutting: about 160g/day.
How Big Should Your Deficit Be?
The size of the deficit mostly trades off speed against how sustainable and muscle-sparing it is:
- Conservative (about 0.25% of body weight/week): 10-15% below TDEE
- Moderate (about 0.5-0.75% of body weight/week): 20-25% below TDEE
- Aggressive (1%+ of body weight/week): 25-30%+ below TDEE
Why Not Just Cut Calories as Much as Possible?
A bigger deficit does lose weight faster at first, but it comes with real costs: more muscle loss alongside the fat, harder adherence, worse training performance, and a bigger metabolic adaptation to fight once you stop. For most people, moderate beats aggressive over any real time frame because it is the one you can actually stick to for months.
A Pound (or Kilo) of Fat Isn't Exactly 3,500 Calories
The commonly cited 3,500 kcal = 1 lb of fat rule is a rough approximation, not a precise conversion. Actual results depend on how much of the loss is fat versus water versus a small amount of muscle, and on how your TDEE itself drops as you lose weight (a lighter body burns fewer calories at rest). Treat any projected timeline as a starting estimate, then recheck it against what the scale actually shows after a couple of weeks.
Protect Muscle While You Diet
Two things matter most in a deficit beyond the calorie number itself: keep protein higher than maintenance (roughly 1.8-2.4 g/kg of body weight) and keep resistance training in your week. Both blunt how much of the weight you lose comes from muscle instead of fat.
Frequently Asked Questions
How many calories should I cut to lose weight?
A deficit of 10-15% below TDEE is a conservative, highly sustainable pace; 20-25% is a moderate pace most people can maintain for months; 25-30%+ is aggressive and harder to sustain, usually reserved for shorter stretches.
How fast should I lose weight?
Roughly 0.5-1% of body weight per week is the commonly recommended range, fast enough to see steady progress, slow enough to protect muscle and keep the diet sustainable.
Is the 3,500-calorie-per-pound rule accurate?
It is a rough approximation, not an exact figure. Real-world results vary with how much of the loss is fat versus water, and your TDEE itself drops somewhat as you lose weight, so treat any timeline projection as an estimate to be checked against actual results.
Why am I not losing weight on a calorie deficit?
The most common culprits are underestimating intake (oils, sauces, and drinks add up fast), overestimating activity-burned calories, water retention masking fat loss, or a deficit that has gotten smaller as your TDEE dropped with your weight. A couple of weeks of honest logging usually reveals which one it is.
Do I need to eat less protein in a deficit to save calories?
No, the opposite. Protein needs go up, not down, in a deficit (roughly 1.8-2.4 g/kg) to protect muscle mass. Cut carbs or fat before cutting protein.
Related tools & guides
The Most Complete Nutrition App
Track your calorie deficit from a photo.
Get your calorie target and macros for fat loss in 30 seconds.
Scientific Sources
- 1. Helms ER, Aragon AA, Fitschen PJ. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 11, 20.
- 2. Jäger R, Kerksick CM, Campbell BI, et al. (2017). International Society of Sports Nutrition Position Stand: Protein and exercise. Journal of the International Society of Sports Nutrition, 14, 20.