Calorie Deficit Calculator

Inputs

Units:
Metric (cm, kg)
Years
Work + leisure training

Mix of standing/walking plus 3-4 workouts.

cm
kg
kg
Keep calorie targets ≥ 1200 kcal/day for adequate nutrient intake. Results are estimates.

Results

BMR

1656 kcal Resting expenditure

Maintenance

2566 kcal TDEE @ Moderate

Recommended target

1925 kcal Balanced (25%)
Plan
Calories
Daily deficit
Weekly change
Gentle (15%)
2181 kcal
385 kcal
0.35 kg/wk (0.77 lb)
Balanced (25%)
1925 kcal
642 kcal
0.58 kg/wk (1.29 lb)
Fast-track (35%)
1668 kcal
898 kcal
0.82 kg/wk (1.80 lb)

Timeline to goal

Est. 14 weeks (~3.2 months) assuming balanced (25%) deficit.

8.0 kg to lose (17.6 lb)

Sources

  • Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. PMID 2305711 — basis for the BMR and TDEE estimate.
  • Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr. 1958;6(5):542–546. PMID 13594881 — origin of the ≈3,500 kcal/lb (7,700 kcal/kg) estimate.
  • Hall KD. What is the required energy deficit per unit weight loss? Int J Obes (Lond). 2008;32(3):573–576. PMID 17848938 · doi:10.1038/sj.ijo.0803720 — why the fixed 3,500 kcal rule is an approximation.

The Calorie Deficit Calculator estimates a daily calorie intake based on the rate at which you want to change weight. You enter your stats, activity level, and goal weight, and the tool estimates your maintenance calories (TDEE), then subtracts a chosen deficit to produce a daily intake figure and an estimated timeline.

A calorie deficit means consuming fewer calories than the body uses over time. This tool presents several deficit sizes (for example 15%, 25%, and 35% of maintenance) so you can compare the resulting intake, daily shortfall, and projected weekly change side by side.

How it works (formula)

  • BMR is estimated with the Mifflin-St Jeor equation. Because this tool does not ask for sex, it uses a single sex-averaged constant (−78), which is the midpoint between the standard male (+5) and female (−161) values; results are therefore an approximation rather than a sex-specific figure.
  • Maintenance (TDEE) = BMR × activity factor (about 1.2 for very light up to 1.9 for very active).
  • Target intake = TDEE − chosen deficit percentage.
  • Estimated weight change uses the conventional value of about 7,700 kcal per kilogram (≈3,500 kcal per pound) of body weight.

The 7,700 kcal/kg figure is a simplified rule of thumb. Research by Hall (2008) shows that the actual energy deficit per unit of weight loss varies with starting body composition and the size of the weight change, so real-world results commonly differ from a straight-line estimate.

All outputs are general estimates for informational and educational purposes and will not reflect any individual's exact energy needs.