Free calculator
Calorie deficit calculator
Safe deficit = 300 to 750 kcal below maintenance, aiming for 0.5% to 1.0% of body weight lost per week.
By Caleb King, founder of CoachhUpdated Formula: TDEE - target deficit, or 7-day rolling weight average
A safe calorie deficit is 300 to 750 calories below your daily maintenance (TDEE), targeting a loss rate of 0.5% to 1.0% of your body weight per week. This calculator works out your target daily calories, projected weekly loss, realistic weeks to your goal, and provides a 7-day rolling average tracker to cut through daily water weight noise.
Calorie deficit & timeline calculator
Find your safe daily deficit, realistic weekly rate, and timeline to your goal weight, or track your 7-day average to ignore water fluctuations.
Your recommended deficit
Estimated pace
~1 lb/wk
(0.6% body weight)
Estimated timeline
~20 weeks
(20 lb total change)
Sustainability
Sustainable: ~0.5% to 1.0% of body weight a week preserves lean muscle.
Want Coachh to handle this automatically?
Logs your food, adapts your calorie targets and programs your sets as your weight moves.
Formulas provide group estimates; individual metabolism and NEAT adapt over time. Coachh tracks your 7-day trend and adjusts targets automatically.
How the calorie deficit is calculated
Weight loss occurs when total energy expenditure exceeds total energy intake over time. One pound of human adipose tissue roughly equates to 3,500 kilocalories of stored chemical energy.
- Daily deficit: TDEE (Maintenance) − Daily Calorie Target.
- Weekly pace: (Daily Deficit × 7) ÷ 3,500 kcal per pound.
- Target date: Total pounds to lose ÷ weekly pace = estimated weeks.
Daily deficit vs weekly fat-loss rate
The table below shows standard deficit sizes and realistic timelines for 10 pounds of fat loss:
| Deficit per day | Weekly loss rate | Time to lose 10 lb | Pace category |
|---|---|---|---|
| 300 kcal | ~0.6 lb / wk (~0.27 kg) | 16.7 weeks | Gentle / High sustainability |
| 500 kcal | ~1.0 lb / wk (~0.45 kg) | 10.0 weeks | Standard / Recommended |
| 650 kcal | ~1.3 lb / wk (~0.59 kg) | 7.7 weeks | Aggressive / Requires high protein |
| 750 kcal | ~1.5 lb / wk (~0.68 kg) | 6.7 weeks | Maximum clinical ceiling |
Why daily weigh-ins lie (and 7-day trends work)
One gram of carbohydrate (stored as muscle glycogen) binds with 3 to 4 grams of water. A carbohydrate-rich dinner can temporarily add 2 to 4 pounds of scale weight by morning, even while you are strictly in a calorie deficit. Conversely, hard sessions cause microtrauma that draws fluid into muscle tissue.
Tracking a 7-day moving average filters out this transient noise, revealing whether your weekly downward trend matches your planned deficit.
Common questions
How big should my calorie deficit be?
A deficit of 300 to 500 kcal per day (~0.5 lb to 1 lb per week) is ideal for most people. The 2013 AHA/ACC/TOS obesity clinical guideline recommends a 500 to 750 kcal daily deficit for initial weight loss. Deficits over 750–1,000 kcal often cause disproportionate muscle loss, lethargy, and compensatory binges.
Why did the scale go up when I'm in a deficit?
Daily scale weight is largely water, glycogen, and intestinal contents. A high-sodium meal, hard strength workout (microtrauma causes muscle inflammation), or poor sleep can hold 2–5 lb of water overnight. Only your 7-day rolling average reveals genuine fat loss.
What is the minimum calorie floor?
Coachh enforces clinical safety floors: never below 1,200 calories per day for women, or 1,500 calories per day for men, unless supervised by a physician. Eating below these floors risks micronutrient deficiencies and metabolic adaptation.
How much protein should I eat in a deficit?
Aim for 1.6 to 2.2 g of protein per kilogram of body weight (0.7 to 1.0 g per pound). Higher protein protects lean muscle tissue from being broken down for fuel while in an energy deficit.
Sources
- 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults. Circulation (Jensen MD, Ryan DH, Apovian CM, et al.), 2014.
- A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition (Mifflin MD, St Jeor ST et al.), 1990.
- Preserving Healthy Muscle during Weight Loss. Advances in Nutrition (Cava E, Yeat NC, Mittendorfer B), 2017.
- Daily self-weighing and adverse psychological outcomes: a randomized controlled trial. Journal of the Academy of Nutrition and Dietetics (Steinberg DM et al.), 2014.