Calorie Calculator for Weight Loss: Free Tool + 1,500-Calorie 7-Day Meal Plan

How Many Calories Do You Need to Lose Weight?

To lose weight, eat fewer calories than your body burns. A daily deficit of about 500 calories below your maintenance calories loses roughly 1 lb a week; 250 calories below loses about half a pound. For most adults that puts a weight-loss target somewhere between 1,200 and 2,200 calories a day. Where you land depends on your size, age, sex and how active you are, which is exactly what the calculator below works out.

Maintenance calories have a name: TDEE, or total daily energy expenditure. It is the calories you burn at rest (your basal metabolic rate, or BMR) multiplied by an activity factor that accounts for everything from walking to the car to a workout. Eat at your TDEE and your weight stays flat. Eat below it and your body makes up the difference from stored energy.

The old rule of thumb that 3,500 calories equals a pound of fat is a simplification. Real weight loss slows as you get lighter, because a smaller body burns less. That is why a calorie target is a starting point you recheck every few weeks, not a number you set once and forget. The NIH Body Weight Planner models that slowdown if you want the long-range view; for the next month, the calculator is plenty.

Calorie Calculator for Weight Loss

Enter your sex, age, height, weight and activity level, then pick a pace. The calculator uses the Mifflin-St Jeor equation, the formula most dietitians start with, to estimate your BMR, multiplies it by your activity level to get your maintenance calories, and subtracts the deficit for your goal. It also gives you a daily protein target, because the protein number matters almost as much as the calorie number on a diet.

Pick your activity level honestly. Most people with a desk job who work out two or three times a week are "lightly active," not "moderately active." Overstating activity is the most common reason a calculated target does not produce the expected loss.

How Accurate Is a Calorie Calculator?

Mifflin-St Jeor is the most accurate of the common resting-calorie equations: in a systematic review, it predicted resting metabolic rate within 10% of the measured value for most adults, better than the older Harris-Benedict formula. The activity multiplier adds more uncertainty than the equation does, so treat your result as accurate to within about 10%, or 150 to 250 calories for most people.

Here is a worked example. A 35-year-old woman who is 5'6" and 180 lb has a BMR of about 1,530 calories. Lightly active, her maintenance is about 2,100 calories, so a 1 lb-a-week target is about 1,600 calories with roughly 130 g of protein. A 40-year-old man who is 5'10" and 220 lb, also lightly active, maintains at about 2,630 and would aim for about 2,130.

The real test is the scale. Follow your target for two to three weeks and compare your average weekly weigh-ins, not single days. If you are losing faster or slower than planned, move your target by 100 to 200 calories and check again. Adaptive apps such as MacroFactor do this math from your weigh-ins automatically; our comparison of the best AI meal planner apps for weight loss covers which tools adjust your target for you and which leave it fixed.

The calculator holds women at 1,200 and men at 1,500 calories minimum, the usual floor for dieting without medical supervision. If your number hits the floor, choose a slower pace or add activity instead of eating less.

The 1,500-Calorie Meal Plan: 7 Days

If your target came out at or near 1,500 calories, which is common for women aiming to lose about a pound a week, this week of meals gets you there. Every day is built protein-first, at roughly 100 to 115 g of protein, with a breakfast around 300 to 350 calories, lunch around 400 to 480, dinner around 500 to 580 and one snack. Daily totals land between 1,420 and 1,500 calories, which leaves a little room for coffee creamer and cooking oil. The weekly average is what moves the scale.

Two dinners carry over into the next day's lunch (salmon on Day 2, chili on Day 5), so two lunches need no cooking. Portions are for one adult; scale dinners up for the rest of the household and keep your own plate measured.

The 1,800-Calorie Meal Plan: 7 Days

An 1,800-calorie target is typical for men losing weight, taller or more active women, and anyone on the slower half-pound-a-week pace. Rather than a second shopping list, this plan keeps the same seven days and adds about 300 calories to each, mostly as protein and fiber. That means one grocery run covers either plan, and two adults on different targets can eat the same dinners from different-sized portions.

Protein-First Macros for Weight Loss

Calories decide whether you lose weight. Protein decides how much of that weight is fat rather than muscle, and how hungry you feel while you lose it. That is why the calculator gives you a protein number: 1.6 g per kilogram of body weight, the low end of the 1.6 to 2.2 g/kg range most evidence-based weight-loss plans use. For a 180 lb person that is about 130 g a day, or roughly 30 to 40 g per meal.

Build each meal around the protein first (chicken, fish, eggs, Greek yogurt, cottage cheese, beans, tofu), add a vegetable, then fill the remaining calories with carbs and fat you enjoy. The two plans above follow that order. Once protein is covered, the carb-to-fat split matters much less than total calories; pick the balance that keeps you full and that you can stick with.

If you want to go deeper on macro splits, cutting versus recomp, and how a planner balances macros across a week rather than plate by plate, read AI Meal Planner for Weight Loss: How to Set Macros and Lose Weight.

How AI Builds the Plan for You

A calculator gives you a number. Hitting that number seven days a week is the hard part: picking meals, checking calories, scaling portions, and writing a grocery list that matches. That planning work is what makes most diets fail by week three, not willpower.

NumYum does that planning for you. Enter your calorie and protein target and the AI builds a full week of breakfasts, lunches and dinners that hit it, built around foods you already like. It plans leftovers on purpose, so you cook fewer nights, and consolidates everything into one aisle-organized grocery list.

It also plans for the people you cook for. Your portion stays measured while the rest of the household eats the same dinner in their own amounts, so you are not making two meals. Every two weeks it asks for a weigh-in and recalculates your target as your weight changes, which is the step people most often skip when they do the math by hand.

If you are comparing tools before you commit, our best AI meal planner app for weight loss guide puts NumYum next to MyFitnessPal, MacroFactor, Lose It! and others. If you are watching the grocery bill as well as the scale, the USDA food plan calculator shows what a realistic weekly food budget looks like for your household.

The Bottom Line

Find your maintenance calories, subtract 250 to 500 a day, set protein at about 1.6 g per kilogram, and follow a plan that hits those numbers for two to three weeks before you adjust. The 1,500 and 1,800-calorie weeks above are a good place to start.

When you would rather not plan every meal yourself, start a free NumYum plan. It takes your target and builds the week, the leftovers and the grocery list in about five minutes.