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Calorie deficit calculator — your daily target.
This calorie deficit calculator turns a weekly loss goal into a daily calorie target. It finds your maintenance calories with the Mifflin-St Jeor equation and your activity level, then subtracts the deficit — about 7,700 calories per kilo of fat — for the pace you pick. Enter your details below; the result updates instantly, no signup.
How fast is safe: aim for about 0.5 to 1 percent of body weight per week. Faster loss risks muscle and adherence; a gentle deficit is easier to hold and to keep off.
The deficit math, explained.
No black box. Maintenance from Mifflin-St Jeor, then a deficit sized straight from your target loss rate.
TDEE = BMR × activity Mifflin-St Jeor BMR — 10 × kg + 6.25 × cm − 5 × age + s — times 1.2 to 1.9 for activity gives the calories that hold your weight steady.
deficit = kg/wk × 7700 ÷ 7 Your weekly loss rate sets the daily gap. About 500 kcal/day lands near 0.45 kg/week; scale up or down from there and subtract it from maintenance.
1 kg fat ≈ 7,700 kcal The fat-energy constant behind every target. It is a solid average, not a law — real loss also moves with water and glycogen.
Worked example: an 80 kg man, moderately active, has a TDEE of about 2,740 kcal. Targeting 0.5 kg/week means a deficit of 0.5 × 7,700 ÷ 7 ≈ 550 kcal/day, so his target is about 2,190 kcal/day. The 7,700-per-kilo figure is an average — track your weight for two to three weeks and adjust intake by 100 to 200 calories if the trend stalls.
Every pace at your stats.
For the details you entered, here is the daily deficit, calorie target, and rough monthly loss at each rate. Change your inputs above and this updates.
| Weekly loss | Daily deficit | Daily calories | ≈ Monthly loss |
|---|---|---|---|
| Enter your details above to see the table. | |||
Who it's for
Anyone who wants to reverse-engineer their intake from a goal loss rate. If you know how fast you want to lose — a gentle 0.25 kg or a brisk 1 kg a week — this tool hands back the exact daily calorie number and deficit to get there, instead of a one-size-fits-all figure. It suits first-time dieters setting a realistic pace, lifters planning a cut, and anyone whose weight has stalled and wants to check their target against the math.
Related nutrition calculators.
See the full picture — your maintenance line, a muscle-sparing cut, and the calories behind every goal.
Calorie deficit questions.
How do I calculate my calorie deficit?
First find your maintenance calories — your TDEE — with the Mifflin-St Jeor equation times your activity factor. Then subtract the deficit for your target loss rate. Because one kilogram of body fat stores about 7,700 calories, losing 0.5 kg a week means a deficit of roughly 550 calories a day. This calculator does all of that from your details, so you get an exact daily number rather than a generic guess.
How big should my calorie deficit be?
A deficit of about 0.5 to 1 percent of body weight per week is sustainable and protects muscle — that is roughly 300 to 550 calories a day for most people. Bigger deficits lose weight faster but cost you more muscle, energy, and adherence. If you are leaner or lifting hard, stay at the gentler end. Never drop below a safe floor of about 1,500 calories for men or 1,200 for women.
How many calories is 1 kg of fat?
One kilogram of body fat stores roughly 7,700 calories, and one pound stores about 3,500. This is the number behind every deficit target — to lose a kilo you need a cumulative deficit of about 7,700 calories, whether that is spread over one week or three. It is an average, not an exact law, because a slice of your weight change is water and glycogen, not pure fat.
Is a 500 calorie deficit enough to lose weight?
Yes — a steady 500-calorie daily deficit adds up to about 3,500 calories a week, close to half a kilogram or one pound of fat lost per week for most people. It is the classic starting point because it is aggressive enough to see progress but gentle enough to sustain. If the scale stalls after two to three weeks, your intake estimate is probably off; tighten your logging before you cut deeper.
How long until I see results in a deficit?
Expect a quick drop of a kilo or two in the first week from water and glycogen, then a slower, steadier trend once fat loss takes over. Judge progress on a two-to-three-week weight trend, not the daily scale — sodium, hydration, and hormones swing day-to-day weight by a kilo or more. If your weekly trend matches your target rate, the deficit is working even when a single morning looks flat.
What if my calorie target falls below the safe minimum?
This calculator caps your target at a safe floor — about 1,500 calories for men and 1,200 for women — and flags it. If your chosen loss rate would push you below that, either slow the pace or add activity to widen the gap through movement instead of eating less. Very low intakes are hard to hold, cost muscle, and usually backfire when hunger wins.
Set your deficit. Hit it daily.
Free in your browser — Nishaana holds your calorie target and logs every meal against it, so your deficit stays real instead of a guess.
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