Calorie deficit calculator
A calorie deficit for weight loss, at a pace you choose.
- Maintenance calories
- 2,560 kcal
- Daily deficit
- 390 kcal
- Loss at first (7,700 kcal per kg)
- 0.35 kg a week
- Resting energy, the floor
- 1,650 kcal
- Protein, 1.6–2.4 g/kg
- 112–168 g a day
For adults 18 and over. An estimate, not medical advice. If you are pregnant or breastfeeding, have or have had an eating disorder, or have a condition or take medicines that affect your weight, ask a doctor or registered dietitian instead.
This calorie deficit calculator turns a weekly pace of weight loss, 0.25 to 1% of your body weight, into a daily calorie target. It starts from your maintenance calories, uses the common rule of 7,700 kcal per kilogram, never sets a target below your resting energy and shows the protein that helps you keep muscle.
- Free, no sign-up
- Kilograms or pounds
- Runs in your browser; nothing is saved
How the calculator works →Coaching clients? Try Trainaq free →
What is a calorie deficit?
A calorie deficit means eating fewer calories than your body uses, so it draws on stored energy and your weight falls. This calorie deficit calculator sizes the deficit from the pace you choose, as a share of your body weight each week, and keeps the target at or above your resting energy.
- Pace as 0.25 to 1% of body weight a week; a 2014 review recommended 0.5 to 1% to keep muscle
- Maintenance estimated from Mifflin-St Jeor and FAO/WHO/UNU activity levels, or typed in
- Never below your estimated resting energy
- A daily protein range to help you keep muscle
How it works
How does this calorie deficit calculator work?
It works in four steps. It estimates your maintenance calories, or takes the figure you know. It turns your chosen pace into kilograms a week and a daily deficit at 7,700 kcal per kilogram. It subtracts that from maintenance, then checks the result against your resting energy and holds it there if needed.
Find your maintenance calories
Maintenance is what you burn in a day. The calculator estimates resting energy with the Mifflin-St Jeor equation and multiplies it by a physical activity level from the FAO/WHO/UNU report, as the TDEE calculator does. If you know your maintenance from tracking your intake and weight, choose that option and type it in.
- A maintenance figure from your own records beats any formula
- The TDEE calculator explains the activity levels
Choose a weekly pace
The pace is a share of your body weight: 0.25, 0.5, 0.75 or 1% a week. A 2014 review of contest preparation for natural bodybuilders recommended losing about 0.5 to 1% a week to keep as much muscle as possible. The 0.25% option is gentler still.
- 80 kg at 0.5% a week is 0.4 kg a week
- A heavier person loses more kilograms at the same percentage
Turn the pace into calories
Each kilogram lost is counted as 7,700 kcal, the common rule of 3,500 kcal per pound. So the daily deficit is the weekly loss in kilograms times 7,700, divided by seven: 1,100 kcal a day for every kilogram a week.
- 0.4 kg a week needs 440 kcal a day
- The rule is an approximation; the accuracy section explains
Hold the floor and keep protein
The target is maintenance minus the deficit, rounded to 10 kcal. If that falls below your estimated resting energy, the calculator holds the target at resting energy and shows the slower pace that gives. It also shows a daily protein range that helps you keep muscle while you lose fat.
- Protein of 1.6 to 2.4 g per kg a day, as in the protein calculator
- Strength training helps keep muscle too
Formulas
Which formulas does the calculator use?
Weekly loss is your weight times the pace. The daily deficit is that weekly loss times 7,700 kcal, divided by seven days. The target is maintenance minus the deficit, but never less than resting energy from Mifflin-St Jeor. Weight is in kilograms; the calculator converts pounds, feet and inches first.
L = W × P ÷ 100D = L × 7,700 ÷ 7 = L × 1,100TDEE = REE × PAL, or your own figureREE = 10 × W + 6.25 × H − 5 × A + 5REE = 10 × W + 6.25 × H − 5 × A − 161Target = the larger of TDEE − D and REE- W: weight in kg; H: height in cm; A: age in years
- P: pace in % of body weight a week; L: weekly loss in kg
- D: daily deficit in kcal; REE: resting energy in kcal a day
- PAL: physical activity level, from the FAO/WHO/UNU report
Paces
Which weekly pace should I choose?
Choose a pace you can keep. In a trial with 24 elite athletes who also lifted weights, those aiming to lose 0.7% a week gained lean mass, while lean mass did not change in those aiming for 1.4%. A 2014 review for natural bodybuilders recommended 0.5 to 1% a week. Slower paces need smaller deficits.
| Pace a week | At 60 kg | At 80 kg | At 100 kg |
|---|---|---|---|
| 0.25% | 0.15 kg · 165 kcal a day | 0.2 kg · 220 kcal a day | 0.25 kg · 275 kcal a day |
| 0.5% | 0.3 kg · 330 kcal a day | 0.4 kg · 440 kcal a day | 0.5 kg · 550 kcal a day |
| 0.75% | 0.45 kg · 495 kcal a day | 0.6 kg · 660 kcal a day | 0.75 kg · 825 kcal a day |
| 1% | 0.6 kg · 660 kcal a day | 0.8 kg · 880 kcal a day | 1 kg · 1,100 kcal a day |
Daily deficit = weekly loss × 7,700 ÷ 7. Helms et al. (2014) recommended 0.5–1% a week; Garthe et al. (2011) compared aiming for 0.7% and 1.4% a week. The calculator also offers 0.25%, a gentler pace.
Worked example
What does a worked example look like?
Take a 30-year-old man, 80 kg and 180 cm, with a desk job. His resting energy is 1,780 kcal and his maintenance about 2,760 kcal. At 0.5% a week he aims to lose 0.4 kg, which needs 440 kcal a day, so his target is about 2,320 kcal.
- At 1% a week: 0.8 kg, an 880 kcal deficit and a target of about 1,880 kcal, still above his resting energy
- A 30-year-old woman, 60 kg and 165 cm, at 0.5% a week: maintenance about 2,050 kcal, a 330 kcal deficit, a target of about 1,720 kcal
- A 40-year-old man, 120 kg and 175 cm: resting energy about 2,100 kcal and maintenance about 3,250 kcal at PAL 1.55
- At 1% a week he would need 1,320 kcal a day off, a target of 1,930 kcal; the floor holds it at about 2,100 kcal, about 1.05 kg a week
The floor
Why does the calculator never go below resting energy?
Resting energy is what your body burns at complete rest, so a target below it means a very large deficit for most people. The calculator treats it as a floor, a cautious rule of its own. If a plan asks you to eat less than that, talk to a doctor or registered dietitian first.
- When the floor applies, the result shows the slower pace you get instead
- Heavier people choosing a fast pace reach the floor first, as in the 120 kg example
- If your own maintenance figure is at or below resting energy, no deficit is set
Accuracy
How accurate is the 7,700 kcal per kilogram rule?
It is a rough guide that overstates loss over months. As you lose weight you burn less, so the same intake gives a smaller deficit. Hall and colleagues modelled this: a lasting cut in intake takes about a year to produce half of its eventual weight change and about three years to produce nearly all of it.
- In their example, a 100 kg man who cuts 480 kcal a day heads for about 75 kg over years, with half of the loss in about the first year
- Leaner people lose more weight per calorie of deficit, because more of what they lose is lean tissue, which holds less energy (Hall 2008)
- Scale readings vary from day to day, so compare weekly averages
- Recalculate when your weight changes: the same pace then gives a smaller deficit
Protein
How much protein should I eat in a calorie deficit?
More than you would at maintenance. The ISSN position stand describes higher intakes helping trained people keep lean mass while eating less, and the protein calculator suggests 1.6 to 2.4 g per kilogram of body weight a day for this goal. Strength training alongside the deficit matters as well.
- The 2014 contest-preparation review gave 2.3 to 3.1 g per kg of lean body mass for lean bodybuilders
- Protein has calories too: count it inside your target, not on top of it
- The same review suggested three to six meals a day, and found timing mattered little for fat loss
Limits
Who should not use a calorie deficit calculator?
Anyone for whom eating less needs medical guidance. That includes people under 18, who are still growing, women who are pregnant or breastfeeding, anyone who has or has had an eating disorder, and people with a medical condition or medicine that affects weight or appetite. A doctor or registered dietitian should set their targets.
- The calculator refuses ages under 18
- If counting calories makes you anxious or leads to bingeing, stop and talk to your doctor
- The 2014 bodybuilding review warned of a higher risk of eating and body image disorders in aesthetic sport
For coaches
How do coaches use a calorie deficit with clients?
Coaches set a deficit as a starting point and adjust it from real data. In Trainaq you set a client’s calorie and macro targets with an effective date, the client logs food in the free Trainaq app, and weekly check-ins with weight and waist show whether the pace is on track.
- Targets keep their history, so you can see when you changed the deficit
- Clients log food by search, barcode or a photo of the meal
- The progress view shows the weight trend beside food logging adherence
Sources
Sources
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20.
- Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011;21(2):97–104.
- Hall KD. What is the required energy deficit per unit weight loss? Int J Obes (Lond). 2008;32(3):573–576.
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826–837.
- Thomas DM, Martin CK, Lettieri S, et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. Int J Obes (Lond). 2013;37(12):1611–1613.
- Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
FAQ
Calorie deficit calculator FAQ
How big a calorie deficit should I aim for?
Size it from your body weight rather than a fixed number. At 0.5% a week, an 80 kg person needs about 440 kcal a day and a 60 kg person about 330 kcal. A fixed 500 kcal deficit is a large share for a small person and a modest one for a large person.
Why am I not losing weight in a calorie deficit?
Usually because the deficit is smaller than planned. Maintenance is an estimate, food logs can miss things, and you burn less as you get lighter. Weigh yourself several mornings a week, compare two- to three-week averages, and if the trend is flat, lower your intake by 100 to 200 kcal a day.
Is losing 1% of body weight a week too fast?
It is the top of the range the 2014 review recommended for keeping muscle, and in the athlete trial the group aiming for 0.7% a week did better on lean mass than the group aiming for 1.4%. If 1% a week leaves you hungry, tired or losing strength, choose a slower pace and give it two to three weeks.
Should I eat back the calories I burn exercising?
Not if your maintenance already includes your training. The activity level in this calculator covers your whole day, workouts included, so adding exercise calories on top would count them twice. If you type in a maintenance figure measured from your own intake and weight, it already reflects your training too.
Can I use this calculator if I am pregnant or a teenager?
No. Pregnancy and breastfeeding raise energy needs, and teenagers are still growing, so a deficit set by formula does not fit either. The calculator refuses ages under 18. If you are pregnant, breastfeeding or under 18 and want to change your weight, ask a doctor or registered dietitian for advice.
When should I recalculate my calorie target?
Recalculate when your weight has changed by a few kilograms or your routine changes. Because the pace is a share of your weight, the same percentage gives a smaller deficit as you get lighter. Between recalculations, let your weekly weight average guide small changes of 100 to 200 kcal a day.
