# Calorie calculator: how many calories a day

> Age, height, weight and activity give your maintenance calories and a target for your goal.

Estimate your daily calories from age, sex, height, weight and activity, then the target to lose, maintain or gain weight, with macros. Runs in your browser.

- Tool: [Calorie calculator](https://fixmint.cc/calorie-calculator)
- Category: [Numbers & dates](https://fixmint.cc/numbers)
- Fixes: How many calories do I need?
- Runs in the browser: files and text stay on the device, no sign-up, free.

## How to work out your daily calories

1. Pick your sex, age, height, weight and how active you usually are.
2. Choose a goal to lose, maintain or gain weight, and a macro split.
3. Read your target calories, the bars for each goal and the grams of protein, carbs and fat.

## Questions

### How are the calories calculated?

Basal metabolic rate (BMR) comes from the Mifflin–St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, then + 5 for men or − 161 for women. Multiplying BMR by an activity factor from 1.2 to 1.9 gives maintenance calories (TDEE). A man of 30, 180 cm and 80 kg has a BMR of 1,780 kcal.

### How are the goal calories worked out?

Body fat holds roughly 7,700 kcal per kilogram, so a daily gap of about 550 kcal adds up to about 0.5 kg a week. This is a planning estimate, not a precise rule: early weight change is mostly water, and the real change varies from person to person.

### What is the lowest calorie intake without medical supervision?

Harvard Health says calorie intake should not fall below 1,200 a day for women or 1,500 a day for men, except under the supervision of a health professional. The tool shows a caution when a target goes below those figures.

### Is this medical advice?

No. It is an estimate from a standard equation, and it cannot measure your metabolism. Talk to a doctor or dietitian before a weight-loss plan, especially if you are pregnant, under 18, or have a medical condition.

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