Calorie Deficit Calculator
Turn a target weight-loss rate into your daily calorie deficit. Get recommended intake, time-to-goal, and safety warnings. Imperial and metric.
Plan your deficit
Don't know yours? Use the TDEE calculator first.
Daily deficit
499 kcal
Eat about 2001 kcal per day to lose 1 lb per week (weekly deficit 3493 kcal).
Per month
4.33 lb
Per year
52 lb
Time to target
20 wk
Educational only, not medical or nutrition advice. Talk to a clinician before a sustained deficit, especially if you take medication, are pregnant, or have a history of disordered eating.
Frequently Asked Questions about the Calorie Deficit Calculator
How is the calorie deficit calculated?
We use the Wishnofsky rule: about 3,500 kcal per pound of body fat, or 7,700 kcal per kilogram. Your weekly deficit is that rule times your target weekly loss, divided by seven for the daily figure. Recommended intake is your TDEE minus that daily deficit.
Is a 1,000 kcal daily deficit safe?
Most clinical guidelines cap sustainable fat loss at 1 to 2 pounds per week, which lines up with a deficit of roughly 500 to 1,000 kcal per day. Above that, the calculator flags it as medically aggressive because the risk of muscle loss, fatigue, gallstones, and rebound weight gain rises sharply.
Why does the calculator warn me below 1,200 kcal per day?
1,200 kcal is a common safety floor for adults. Below it, hitting basic micronutrient targets (iron, calcium, B12, protein) without a planned program becomes hard, and many people see metabolic slowdown and disordered-eating patterns. Very low calorie diets exist, but they are supervised medical interventions, not DIY plans.
Will I actually lose weight at the rate this calculator predicts?
Probably not exactly. The Wishnofsky rule is a flat, linear approximation. In reality, your TDEE drops as you lose weight, water swings can mask fat loss for weeks, and adherence to the deficit is rarely perfect. Use the result as a starting point and re-check every 4 to 6 weeks instead of treating it as a guarantee.
Is this medical or nutrition advice?
No. Calculator+ is an educational tool. It does not know your health history, medications, pregnancy status, training load, or eating-disorder history, all of which change what a safe deficit looks like for you. Talk to a registered dietitian or your doctor before starting a sustained calorie deficit, especially if you have a medical condition or are under 18.
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