How many calories to lose weight?
Enter your weight, choose how fast you want to lose, and get the exact daily calorie and protein target that puts you in a deficit. Free, no signup.
What the calorie deficit number means
Your body burns a certain number of calories every day just living, moving, and digesting food. That total is your maintenance level. Eat below it and you create a calorie deficit; your body covers the gap by burning stored fat, and the scale goes down. Eat at it and your weight holds steady. That's the entire mechanism of fat loss - no special foods, no magic timing.
The calculator above builds the deficit in for you. “Lose Slow” sets a gentle deficit that's easy to sustain; “Lose Fast” sets a steeper one for quicker results. Most people do best somewhere in the slow-to-moderate range - around 300-500 calories under maintenance - because the deficit you can keep beats the aggressive one you abandon in two weeks.
Roughly what to expect
Estimates only - real results vary with activity, body size, and consistency. Don't drop below ~1,200 cal (women) or ~1,500 cal (men) without medical guidance.
Knowing your number is step one. The part that actually moves the scale is hitting it most days - which is what FitLog's simple meal logging is for.
From deficit to results
A deficit is defined relative to your maintenance calories, and it works best when you hit your daily protein target to keep muscle. If you just want a quick answer to how many calories you should eat a day, that's covered too.
Common questions
A calorie deficit means eating fewer calories than your body burns in a day. When that happens, your body makes up the difference using stored energy - mostly body fat - and you lose weight. A deficit is the one thing every successful fat-loss diet has in common, regardless of which foods or eating windows it uses.
For most people a moderate deficit of about 300-500 calories below maintenance works best. It produces steady fat loss of roughly 0.5-1 lb per week while preserving muscle and keeping hunger manageable. Larger deficits lose weight faster but are harder to sustain and risk muscle loss. As a safety floor, most guidance suggests not eating below about 1,200 calories for women or 1,500 for men without medical supervision.
Instead of a complex BMR formula, FitLog uses the bodyweight multiplier method: your bodyweight in pounds times a multiplier based on how fast you want to lose. Choosing 'Lose Slow' applies roughly an 11x multiplier and 'Lose Fast' an 8x multiplier, which build the deficit in automatically. It is simpler, fast, and accurate enough to make consistent progress.
Protein is what protects your muscle while you are in a deficit, so the weight you lose comes from fat rather than lean mass. It also keeps you fuller, which makes the deficit easier to maintain. FitLog targets about 1g of protein per pound of bodyweight per day.
Yes. As you get lighter your body burns fewer calories, so your maintenance level drops and your target comes down with it. Because FitLog bases your number on your current bodyweight, you simply recalculate every few weeks as the scale moves.