Free Calorie Deficit Calculator — Safe Targets & Weekly Rates (2026)
Find your maintenance calories (TDEE) and three deficit tiers with realistic weekly rates — including a warning when a target dips below your BMR. Then turn the target into a USDA food plan. Free.
A deficit only works if it's anchored to the right starting number: your maintenance calories. Enter five details and get your TDEE plus three deficit tiers — mild, standard, and aggressive — with the weekly rate each one realistically buys, and a flag when a target crosses below your BMR.
What is a calorie deficit?
A calorie deficit means eating fewer calories than your body uses in a day. Your body covers the gap from its stored energy, so your weight goes down over time.
The size of the gap sets the pace. This calculator offers three paces: 250, 500 and 750 calories a day below your maintenance, the calories that keep your weight steady. On paper, those come to about 0.5, 1 and 1.5 lb a week.
How to calculate your calorie deficit
Here is the math the calculator above does, step by step, for a moderately active 35-year-old woman who is 5 ft 3 in (160 cm) tall and weighs 172 lb (78 kg).
- Find your BMR, the calories your body burns at rest, with the Mifflin-St Jeor equation. For women it is 10 × weight in kg + 6.25 × height in cm − 5 × age − 161. For men, the last step is + 5 instead of − 161. In the example: 10 × 78 + 6.25 × 160 − 5 × 35 − 161 = 1,444 calories.
- Multiply by your activity level to get your maintenance calories, also called TDEE. In the example: 1,444 × 1.55 = 2,238 calories a day. The table below has every multiplier.
- Take away your deficit. In the example: 2,238 − 500 = 1,738 calories a day. Over a week that is 3,500 calories, about 1 lb (0.45 kg).
- Check the target. Keep it above your BMR and at least 1,200 calories a day for women or 1,500 for men, the lowest targets in the 2013 U.S. obesity guideline. The example's 1,738 is above its BMR of 1,444, so it passes.
| Activity level | Multiply your BMR by |
|---|---|
| Sedentary | 1.2 |
| Moderately active | 1.55 |
| Active | 1.725 |
| Very active | 1.9 |
Picking a deficit size
A starting deficit is slow on purpose: enough to mostly preserve muscle and sane enough to sustain for months — which is what actually determines success, more than the size of the cut itself. The tiers above show what each pace trades away.
Bigger deficits buy faster scale movement at compounding costs: more hunger, more muscle loss, more fatigue, and far worse adherence. If a tier on this page is flagged below your BMR, treat it as a conversation with a professional, not a plan.
Why the weekly rates are approximate
The classic arithmetic — about 7,700 kcal per kilogram (3,500 per pound) — is a planning approximation, not a law. Metabolism adapts as you lose weight, water shifts mask fat changes week to week, and maintenance itself drifts downward as you get lighter.
The practical loop: pick a tier, run it for three weeks, compare the scale's weekly average against the prediction, and adjust 100–200 kcal at a time. Recalculate here every ~5 kg.
Formula & sources
Resting calories (Mifflin-St Jeor BMR)
W = weight in kg, H = height in cm, A = age in years. Result in kcal/day.
Maintenance calories (TDEE)
The calories that keep your weight steady at your activity level. The deficit comes off this number.
Daily intake target
Approximate weekly change
The Wishnofsky ~7700 kcal/kg (3500 kcal/lb) rule of thumb. It overstates long-run loss as the body adapts, so treat the weekly figure as a first approximation.
Lowest daily target offered
A pace whose target falls under this is not offered. It is the low end of the calorie range both guidelines below give for weight loss.
| Sex | kcal per day |
|---|---|
| Women | 1,200 |
| Men | 1,500 |
Sources
- Mifflin MD, St Jeor ST, et al. (1990) A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 51(2):241–247.
- Activity-factor scale The conventional activity multipliers used with the Harris-Benedict and Mifflin-St Jeor equations: 1.2 sedentary, 1.55 moderately active, 1.725 active, 1.9 very active. A widely used convention, not taken from a single study.
- Wishnofsky M (1958) Caloric equivalents of gained or lost weight. Am J Clin Nutr 6(5):542–546 — the origin of the 3500 kcal/lb approximation.
- Thomas DM, Martin CK, Lettieri S, et al. (2013) 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 37(12):1611–1613.
- Jensen MD, Ryan DH, Apovian CM, et al. (2014) 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation 129(25 Suppl 2):S102–S138. Recommendation 3a: 1,200 to 1,500 kcal/day for women and 1,500 to 1,800 for men, or a deficit of 500 or 750 kcal/day.
- Academy of Nutrition and Dietetics (2014) Adult Weight Management Evidence-Based Nutrition Practice Guideline, Caloric Reduction and Nutrient Adequacy: the same calorie ranges and deficits.
Calorie deficit questions, answered
How many calories should I cut to lose weight?
Start 250–500 kcal/day below your TDEE. That produces roughly 0.25–0.5 kg (0.5–1 lb) per week for most people — fast enough to see progress, slow enough to keep muscle and sanity.
Is a 500-calorie deficit safe?
For most healthy adults, yes: it is the usual starting point. The limit to watch is your daily target, not the deficit. If your maintenance minus 500 lands below your BMR, or below 1,200 calories a day for women or 1,500 for men, work with a doctor or dietitian instead of pushing through.
Do you lose a pound a week with a 500-calorie deficit?
On paper, yes: 500 calories × 7 days = 3,500, the classic figure for one pound of body weight. In practice it is usually less. A 2013 study in the International Journal of Obesity found that the 3,500-calorie rule overestimates real weight loss. One reason is that your maintenance falls as you lose. Use the weekly figure as a starting point and compare it with your scale after three weeks.
How long does it take to see results in a calorie deficit?
At a 500-calorie deficit, about 1 lb (0.45 kg) a week on paper, so 10 lb takes about 10 weeks. Enter your goal weight in the calculator above to get your own date. Real loss usually runs slower, because your maintenance drops as you get lighter, so recalculate every 5 kg (11 lb).
Is a 1,000-calorie deficit safe?
Only when your maintenance is high, and it is best done with a doctor or dietitian. A 1,000-calorie deficit comes to about 2 lb (0.91 kg) a week, the top of the 1 to 2 lb a week that the CDC calls a gradual, steady pace. Your daily target still has to stay above your BMR and at least 1,200 calories for women or 1,500 for men. This calculator stops at 750 a day.
Why am I not losing weight in a deficit?
Usually one of three things: portions have crept up, your body burns less than the equation estimates, or water is hiding fat loss. Three weeks of steady tracking usually shows which.
Should I eat back exercise calories?
If you chose an activity level that already includes your training, no — they're already in your TDEE. Counting them twice is the most common way deficits quietly disappear.
How fast is too fast?
The CDC calls about 1 to 2 lb a week a gradual, steady pace. The fastest pace here, 750 calories a day below your maintenance, comes to about 1.5 lb a week on paper. To lose faster, work with a doctor or dietitian.
How much protein should I eat in a calorie deficit?
Aim for the daily range in the results above. It comes from your weight and activity, not your calories, so keep it steady while calories drop: protein then becomes a bigger share of a smaller plate. The protein calculator shows how the range is worked out. The RDA, 0.8 g per kg of body weight, is the minimum to avoid a shortfall, not a target for keeping muscle while you cut.
What should I actually eat in a deficit?
That's the question this site exists for: the MyPlate Plan translates a calorie level into food groups — produce, grains, protein, dairy — so the deficit is built from a balanced plate rather than willpower alone.
Can I use this calculator if I'm pregnant, breastfeeding or under 18?
Not for a weight-loss target: the calculator shows none in those cases. Its equations and paces are for adults who are not pregnant or breastfeeding. The MyPlate Plan covers pregnancy, breastfeeding and children from age 2, so start there.