Free calculator
Cutting calorie calculator
Estimate a calorie deficit for losing fat while keeping muscle. Pick how aggressive the cut is instead of letting a formula decide for you.
Your starting point
Estimated daily target
- Protein
- 127g
- Fat
- 61g
- Carbs
- 281g
- Estimated maintenance
- 2,728 kcal
- Estimated resting needs
- 1,760 kcal
- Daily adjustment
- -20%
Treat this as a starting estimate. Track your average body weight for 2 to 3 weeks, then adjust calories in small steps if your trend does not match your goal.
How it works
Lose fat at a rate you can keep up.
The calculator estimates maintenance with the Mifflin-St Jeor equation and your activity level, then removes 10%, 20%, or 25%. For most people a 20% deficit lands near the 0.5% to 1% of body weight per week that bodybuilding contest-prep research found preserves lean mass best.
Protein stays at 1.6 g/kg even as calories fall, because that is the intake at which the resistance-training literature stops showing extra muscle gain, and in a deficit it is the macro doing the most work. Fat is held at 25% of calories, and carbohydrate takes the remainder.
A 25% deficit is faster but harder to sustain and more likely to cost muscle and training quality. Use it for short blocks with a clear end date, not as a default.
Sources and limitations
- 1. Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals.
- 2. Helms ER et al. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation.
- 3. Morton RW et al. Protein supplementation and resistance training meta-analysis.
- 4. National Academies. Acceptable Macronutrient Distribution Ranges.
This calculator is for generally healthy adults ages 19 to 78. It is not medical advice and is not intended for pregnancy, breastfeeding, eating disorders, or medical nutrition therapy. Predictive equations can differ from measured energy needs by several hundred calories. For a dynamic weight-change model, see the NIH Body Weight Planner or speak with a registered dietitian.
Cutting FAQ
How many calories should I cut to lose fat?
A 20% deficit below maintenance is a reasonable default. It usually produces a loss of about 0.5% to 1% of body weight per week, which is the range research associates with keeping muscle.
Is a 500-calorie deficit right for everyone?
No. A fixed 500 calories is a large cut for a small person and a small one for a large person. A percentage of maintenance scales with your actual needs.
What if I stop losing weight?
Compare weekly averages, not single days. If the average is flat for two to three weeks, remove another 5%, or add a little activity. Do not stack changes on top of each other.
Not sure what your maintenance is? Start with the TDEE calculator. Trying to lose fat and gain muscle at once? The body recomposition calculator.
No trial. No asterisk.
Turn this number into a habit.
Silent tracks the deficit you just picked and shows the weekly weight trend that tells you if it is working. $3.99, once.