BMR Calculator

Calculate your BMR:

Find the average amount of calories you need based on your lifestyle. BMR isn't used to check eligibility for weight loss treatment, but you can use our BMI calculator.

Important: These are estimates based on height and weight averages. You should always talk directly to a clinician for a truly accurate measurement. 

How to use our BMR calculator:

To check your BMR with our calculator, you’ll need to enter your gender, age, height, and weight in imperial or metric units. After that, hit calculate, and we’ll calculate your BMR.

How we calculate your BMR:

Mifflin-ST Jeor formula

Our calculator works out your BMR using the ‘Mifflin-ST Jeor’ equation. This is considered the most accurate way of working out BMR. For men, this formula is:

 Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5

Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) – 161

You can use this formula to calculate it yourself, but our calculator spares you the math and gives you the most accurate result.

Harris Benedict formula

This formula is used with your BMR to calculate how many calories you need depending on your activity level. It looks like this:

• Little/no exercise: BMR multiplied by 1.2 = Total calories needed
• Light exercise: BMR multiplied by  1.375 = Total calories needed
• Moderate exercise (3-5 days a week): BMR multiplied by  1.55 = Total calories needed
• Very active (6-7 days week): BMR multiplied by  1.725 = Total calories needed
• Extra active (very active & physical job): BMR multiplied by  1.9 = Total calories needed

Is this BMR calculator accurate?

Yes – if you enter your details correctly, our BMR calculator will give you an accurate result based on your information. It’s also important to remember that BMR is affected by your lifestyle, so we provide estimates based on how active you might be, but this is only an estimate.

If you’re ever concerned about a result or need more advice about BMR, you should speak directly to a clinician.

What does this calculator tell me?

Our calculator will give you a BMR number. This number represents how many calories you need a day at complete rest.

Depending on your activity level, it will also estimate how many calories you would need.

It will provide estimates for if you’re:

• Sedentary
  Getting little or no exercise
• Lightly active
  Light exercise  1-3 days a week
• Moderately active
  Moderate exercise 3-5 days a week
• Very active
  Hard exercise 6-6 days a week
• Extra active
  Very hard exercise & a physical job or training twice a day

Understanding how many calories you need in a day makes it easier to build a clear picture of how many calories you need to eat to lose or maintain weight. And that’s precisely what our calculator will tell you.

Important: Your activity level will change your BMR, but it’s important to remember that you’re not telling us exactly how active you are, so these are only estimates.

“BMR is a great tool for better understanding how many calories you need to eat a day to maintain your weight. For example, the average daily calories recommended for men is around 2500 and for women around 2000, but these don’t consider all the different shapes people are in or how active you might be! So while still an estimate, BMR can give you a clearer picture of how many calories your body actually needs so you can work out a diet plan that meets your weight loss objectives.”

Ian Budd, Prescribing Pharmacist

Do I need to calculate my BMR to get weight loss treatments?

No. BMR is not used to determine eligibility for weight loss treatment. For weight loss treatment, you will need to find out your BMI.

BMR is a tool for calculating the number of calories needed so you can plan a diet better suited to your weight loss goals.

Learn more about BMR and how it affects you.