The BMR Calculator is a free tool that helps you calculate bmr using the formula Mifflin-St Jeor: BMR = 10xkg + 6.25xcm - 5xage + (5 male / -161 female). Enter your values above and press Calculate to get bmr instantly, with a full step-by-step breakdown.
What is the BMR Calculator?
The bmr calculator is a free online tool that helps you calculate bmr quickly and accurately. It applies the standard formula Mifflin-St Jeor: BMR = 10xkg + 6.25xcm - 5xage + (5 male / -161 female) to the values you enter and, when you press Calculate, displays the result together with a clear, step-by-step explanation of how the answer was reached.
Also known as: basal metabolic rate calculator, metabolic rate calculator, bmr formula, bmr calculator to lose weight, rmr calculator.
How to use the BMR Calculator
- Choose your gender.
- Enter age, weight and height.
- See your basal metabolic rate.
Formula used
The bmr calculator is based on this formula:
Mifflin-St Jeor: BMR = 10xkg + 6.25xcm - 5xage + (5 male / -161 female)Each term in the formula corresponds to one of the inputs explained below. The calculator performs the arithmetic for you and shows every step so you can check the working by hand if you wish.
Worked example
Suppose you enter Male, 30y, 70kg, 170cm. The calculator works as follows:
| Inputs | Male, 30y, 70kg, 170cm |
|---|---|
| Working | 10x70 + 6.25x170 - 5x30 + 5 |
| Result | BMR about 1617 kcal/day |
Step-by-step calculation
- Apply the formula:
Mifflin-St Jeor: BMR = 10xkg + 6.25xcm - 5xage + (5 male / -161 female) - Substitute your values: 10x70 + 6.25x170 - 5x30 + 5
- Read the result: BMR about 1617 kcal/day
Activity multipliers used for daily calories
| Activity level | Multiplier (ร BMR) |
|---|---|
| Sedentary (little/no exercise) | 1.2 |
| Lightly active (1โ3 days/week) | 1.375 |
| Moderately active (3โ5 days/week) | 1.55 |
| Very active (6โ7 days/week) | 1.725 |
| Extra active (hard daily training) | 1.9 |
Inputs explained
- Gender โ the gender used in the calculation.
- Age (years) โ the age used in the calculation.
- Weight (kg) โ the weight used in the calculation.
- Height (cm) โ the height used in the calculation.
Understanding your result
- BMR โ the calculated bmr in kcal/day.
Benefits and practical uses
The bmr calculator saves time and removes the risk of manual errors when you need to calculate bmr. It is useful for students, professionals and anyone who wants a fast, dependable answer. Results update the moment you press Calculate, work on any device, and can be copied or shared in a single click โ and because the maths runs in your browser, your figures stay completely private.
Tips for an accurate result
- Keep all related inputs in the same units.
- Use the worked example above to confirm you are entering values in the right places.
- Review the assumptions below so the result fits your situation.
- Press Reset to clear everything and try a different scenario.
Common mistakes to avoid
- Entering values in the wrong unit (mismatched units give wrong answers).
- Leaving a required field empty โ the calculator will ask you to fill it in.
- Treating the result as a diagnosis instead of a general guide.
Assumptions and limitations
- Mifflin-St Jeor equation.
- Healthy adults.
Frequently asked questions
What is BMR?
Basal Metabolic Rate is the energy your body burns at complete rest to keep vital functions running.
How do I get daily calorie needs?
Multiply BMR by an activity factor (1.2 sedentary to 1.9 very active) to get TDEE.
How do I use the BMR Calculator?
Enter your values in the fields, then press the Calculate button to see the result. Use Reset to clear the form and start again. Nothing is calculated until you click Calculate.
What formula does the BMR Calculator use?
It uses the standard formula: Mifflin-St Jeor: BMR = 10xkg + 6.25xcm - 5xage + (5 male / -161 female). The full step-by-step working is shown with every result so you can verify it.
What information do I need to use the bmr calculator?
You need: gender, age, weight, height. Sensible example values are pre-filled so you can see how it works.
Is the BMR Calculator free to use?
Yes. Every DigiToolkit calculator is completely free, with no sign-up, no login and no usage limits.
Does the BMR Calculator work on mobile phones?
Yes. The calculator is mobile-first and works on phones, tablets and computers in any modern browser.
Do I need to install an app?
No. The bmr calculator runs directly in your web browser โ there is nothing to download or install.
Is my data private when I use this calculator?
Yes. All calculations run inside your browser. The numbers you enter are never uploaded to a server or shared with anyone.
How accurate is the BMR Calculator?
It uses the generally accepted formula for bmr and computes to several decimal places. Results are accurate for the assumptions listed on this page.
Can I copy or share my result?
Yes. After calculating, use the Copy button to copy the result, or Share to copy the page link.
Why is nothing showing until I press Calculate?
By design, the calculator only computes when you press Calculate, so you can finish entering all your values first. Press Reset any time to clear everything.