Calorie Calculator
Estimate your daily calorie needs for maintaining, losing, or gaining weight.
How it works
This calculator estimates your Total Daily Energy Expenditure (TDEE) — roughly how many calories your body burns in a day — and then shows adjusted targets for maintaining, losing, or gaining weight.
It starts with your Basal Metabolic Rate (BMR), the calories your body burns at complete rest just to keep you alive, using the Mifflin-St Jeor equation (the most widely validated BMR formula). It then multiplies BMR by an activity factor based on how active you are day-to-day, ranging from 1.2 (sedentary) to 1.9 (extremely active), to estimate maintenance calories.
For example, a moderately active person with a BMR of 1,600 calories has a maintenance estimate of 1,600 × 1.55 ≈ 2,480 calories per day — the amount needed to keep weight stable.
From that maintenance number, the calculator shows mild and standard targets for weight loss (subtracting roughly 250 or 500 calories/day) and weight gain (adding roughly 250 or 500 calories/day). A 500-calorie daily deficit or surplus corresponds to roughly 1 lb (about 0.45 kg) of weight change per week, since one pound of body fat represents approximately 3,500 stored calories — though real-world results vary by individual.
These numbers are a starting estimate, not a guarantee — actual metabolism varies by individual beyond what any formula captures, and factors like sleep, stress, and muscle mass all play a role. Track your actual weight trend over 2–3 weeks and adjust the calorie target up or down if real results don't match the estimate.
Total calories are only part of the picture — how those calories break down into protein, fat, and carbohydrates (macronutrients) affects things like muscle retention during weight loss and satiety throughout the day. Once you have a calorie target from this calculator, the Macro Calculator can turn it into specific protein, fat, and carb gram targets.
A common pitfall with calorie tracking is underestimating actual intake — cooking oils, sauces, dressings, and drinks are easy to forget but add up quickly, which is often the real reason someone doesn't see expected progress despite believing they're eating at a deficit. Another common pattern is a weight-loss plateau after initial progress, which usually reflects the fact that TDEE drops somewhat as body weight decreases (a lighter body burns fewer calories at rest), meaning the same calorie target that worked initially may need a downward adjustment over time.
How much of a deficit is safe?
A 500 cal/day deficit roughly targets 1 lb (0.45 kg) of loss per week; consult a professional for personalized advice.
How is BMR different from calorie needs?
BMR is calories burned at complete rest; total calorie needs multiply BMR by an activity factor to account for movement and exercise throughout the day.
Do I need to recalculate as I lose or gain weight?
Yes — BMR and TDEE both depend on your current weight, so recalculating every 10–15 lbs (or every few weeks during active weight change) keeps the estimate accurate.
Does this calculator account for muscle mass?
Not directly — the Mifflin-St Jeor formula uses weight, height, age, and sex, not body composition, so it may slightly under- or overestimate calorie needs for people with unusually high or low muscle mass.
How accurate are the activity level multipliers?
They're reasonable estimates based on general activity categories, but everyone's actual daily movement varies — treat the result as a starting point to adjust from based on real-world weight trends.
Should I eat back calories burned from exercise?
If you selected an activity level that already reflects your typical exercise routine, no — that activity is already factored in. Only add back calories for exercise that's unusually intense or infrequent relative to your selected activity level.
What if I want to gain weight instead of lose it?
Use the gain targets shown, which add roughly 250–500 calories to your maintenance number — combined with resistance training, this supports gradual, mostly lean weight gain rather than rapid fat gain.
Why did my weight loss stall even though I haven't changed anything?
As body weight decreases, TDEE typically decreases too, since a lighter body burns somewhat fewer calories at rest and during activity — a calorie target that created a deficit initially may need to be lowered again after meaningful weight loss.
How do I turn a calorie target into a meal plan?
Start by splitting the calorie target into protein, fat, and carb grams (the Macro Calculator does this), then build meals around hitting those targets — tracking food intake for a week or two is the most reliable way to see whether real intake matches the plan.