Weight Loss Date Calculator: Calorie Deficit to Goal Weight

Calorie deficit and goal date: how weight loss is projected

The planner multiplies the kilos to lose by 7,700 kcal and divides by your chosen daily deficit to get a number of days, then a date. A 500 kcal daily deficit is about 0.45 kg (1 lb) a week, so losing 11 kg takes 170 days. Daily intake never goes below 1,200 kcal for women or 1,500 kcal for men.

Calculation

• Mifflin-St Jeor BMR, then TDEE = BMR × 1.2, 1.375, 1.55 or 1.725. Input is in pounds and inches by default; the maths runs in kilos.
• Target intake = TDEE − deficit (300, 500, 750 or 1,000 kcal), with a floor of 1,200 kcal (women) or 1,500 kcal (men).
• Days = (current weight − goal weight) × 7,700 ÷ real deficit (TDEE − target intake), rounded up; the date counts from today.
• Weekly loss = real deficit × 7 ÷ 7,700: 0.27 kg at 300 kcal, 0.45 kg at 500, 0.68 kg at 750, 0.91 kg at 1,000.
• Macros: high protein 40/30/30 (protein/carbs/fat), balanced 35/40/25, low carb 35/20/45.

Example

Woman, 32, 168 cm, 75 kg, goal 64 kg, lightly active, 500 kcal deficit: BMR = 750 + 1,050 − 160 − 161 = 1,479 kcal; TDEE = 2,034 kcal; target intake 1,534 kcal. 11 kg × 7,700 = 84,700 kcal, i.e. 170 days (24.3 weeks). Protein 153 g, carbohydrates 115 g, fat 51 g.

Limits

When the floor applies, the date, the weekly pace and the deficit shown follow the real deficit. At 1,000 kcal in the example, intake is held at 1,200 kcal: the real deficit drops to 834 kcal, giving 102 days instead of 85 and 0.76 kg a week. For a sedentary 55-year-old woman, 160 cm and 65 kg aiming for 58 kg at 1,000 kcal, only 257 kcal of deficit remain: 210 days. If expenditure is already below the floor, the goal is shown as not reachable. These floors are the tool's own choice, not an official threshold; the "healthy and sustainable" note only appears for a real deficit of 500 kcal or less, with no floor. The 7,700 kcal rule overstates long-term loss because expenditure falls as weight drops. Discuss a large deficit with a doctor. See also the BMR/TDEE, TDEE and macro, and TDEE and deficit calculators.

Sources and dates: Mifflin et al., 1990; 7,700 kcal per kg convention (3,500 kcal per pound, Wishnofsky, 1958), discussed by Hall et al. (The Lancet, 2011); ANSES, protein (22/12/2025); ANSES, fats (15/03/2021); EFSA, protein (09/02/2012) (checked 14/10/2026).

Frequently Asked Questions

How many calories do I need to burn to lose 1 kg?

The tool uses the convention of 7,700 kcal per kilo of fat, or 3,500 kcal per pound. With a 500 kcal daily deficit, that is about 15.4 days per kilo, or 0.45 kg (1 lb) a week. Over time, actual loss slows because energy expenditure falls with weight.

How does the planner calculate the goal date?

It multiplies the kilos to lose by 7,700, divides by the daily deficit, rounds up to a whole day and adds that number of days to today's date. For 11 kg at 500 kcal a day: 84,700 ÷ 500 = 169.4, i.e. 170 days or 24.3 weeks.

Why does the calculated intake not go below 1,200 kcal?

The tool sets a floor of 1,200 kcal for women and 1,500 kcal for men; this is the tool's own choice, not an official threshold. When the floor applies, the real deficit is smaller than the one chosen: the date and the weekly pace are then worked out from that real deficit, and the goal is shown as not reachable if expenditure is already below the floor.

Which deficit should I pick: 300, 500, 750 or 1,000 kcal?

These options give 0.27, 0.45, 0.68 and 0.91 kg a week. Losing 11 kg takes 283, 170, 113 or 85 days depending on the pace, provided the floor does not apply. Above 500 kcal a day, or with a health condition, talk to a doctor or dietitian.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.