Macro and calorie calculator
Work out how many calories you need each day, and how much protein, carbs and fat. We use the same sums as the Susten app.
- Every step of the sum shown
- Nothing you type leaves this page
- Then a week of meals at your numbers
Your age, gender, height and weight stay on this page. We don't send them anywhere or store them.
Your numbers show here.
Answer the questions, then press See my numbers. You get calories, protein, carbs and fat, from the same sums the Susten app uses.
- Protein
- Not worked out yet
- Carbs
- Not worked out yet
- Fat
- Not worked out yet
An estimate for healthy adults, not medical advice. About these numbers
How the calculator works
The sums behind your numbers, step by step. The Susten app uses the same ones.
How we work out your calories
We start with the calories your body uses at rest. We work them out with the Mifflin-St Jeor equation, a standard formula for it:
- Men: 10 × weight in kg + 6.25 × height in cm − 5 × age + 5
- Women: 10 × weight in kg + 6.25 × height in cm − 5 × age − 161
Then we multiply by your activity level. That gives the calories you burn in a day, which some calculators call your TDEE.
| Activity level | What it means | Multiply by |
|---|---|---|
| Not active | A desk job and little or no exercise. | 1.2 |
| Lightly active | Exercise 1 to 3 days a week. | 1.375 |
| Moderately active | Exercise 3 to 5 days a week. | 1.55 |
| Active | Hard exercise 6 or 7 days a week. | 1.725 |
| Very active | Hard exercise every day, or a physical job. | 1.9 |
Last, your goal. To lose weight, we take 500 kcal off. To build muscle, we add 300. To stay at your weight, we leave it as it is. A fixed step is easy to plan a week around. You can change your calories in the app later.
How we split your macros
Protein comes first. We set it by your body weight, not as a share of your calories. How much for each kg depends on your goal and how active you are:
| Goal | Not active | Lightly active and up |
|---|---|---|
| Lose weight | 1.6 g | 1.8 g |
| Build muscle | 1.6 g | 2.0 g |
| Stay at my weight | 1.4 g | 1.6 g |
Your protein needs follow your muscle, not your whole weight. So if your BMI is over 25, we use the weight that gives a BMI of 25 at your height. To build muscle, we use a BMI of 27: people who lift carry more muscle for their height.
We cap protein at 60% of your calories. Fat is 30% of your calories, and carbs make up the rest. To turn those shares into grams, protein and carbs have 4 kcal in each gram and fat has 9.
A target is not a plan
Most calculators stop at the number. Then you have to find meals that add up to it, every day of the week, and buy the food for them. That's why a target written down on Sunday is forgotten by Wednesday.
Susten does that part. It plans every meal of your week to your calories, protein, carbs and fat. Then it writes your shopping list and matches each item to a Tesco or Sainsbury's product. The Susten app uses these same sums, so your numbers there match the numbers here.
A good week starts with one decision, not seven.
Answer a few questions. Susten plans your first week.
- No card needed
- Free while we build it