BMR Calculator
Basal metabolic rate (Mifflin-St Jeor).
How to use BMR Calculator
BMR Calculator: Estimate your basal metabolic rate with the Mifflin-St Jeor equation. It is built for speed and privacy: open the page and start, with no account required.
BMR Calculator is straightforward to use. The output is produced by standard arithmetic applied only to the numbers you type, so it updates the instant you change an input and never depends on a server. Because the work happens locally, there is nothing to install and no waiting on a network.
Open BMR Calculator on toolpermarket. The tool loads instantly and runs entirely in your browser, so you can begin right away without creating an account.
In the Age, weight, height field, enter your stats in the requested units. Use kilograms and centimeters for the Mifflin formula.
In the Sex field, pick the biological option the formula expects. It adjusts the constant because body composition differs.
Press Calculate to compute the result. The output appears immediately below the form, and you can change any input and run it again as many times as you like.
Read the result and use it as needed. If anything looks off, double-check your inputs and run it again — the calculation is local and instant, so experimenting costs nothing.
Worked example. A 30-year-old, 70 kg, 175 cm person has a BMR near 1,550 calories a day at complete rest.
Tips for accurate results.
BMR is at rest — add activity to get daily needs.
Use it as the floor, not your full calorie target.
Recompute after notable weight or age changes.
When to use BMR Calculator. Estimating baseline calorie burn. Setting a deficit or surplus from a known floor. Understanding why two people differ at rest.
Why use an online calculator tool. A dedicated tool like BMR Calculator saves the time you would spend opening a spreadsheet, writing a formula, or installing software. It is free, works in any browser, and keeps your input private — handy for a one-off calculation or a quick check while you work.
Everything stays on your device. BMR Calculator performs no network calls, uploads, or tracking — your input is processed locally and forgotten the moment you close the tab.
Frequently asked questions
What is BMR versus TDEE?
BMR is the calories you burn at complete rest, just keeping alive. TDEE adds your daily activity on top. The calculator reports the resting floor; multiply or add activity to estimate total daily expenditure, which is the figure most diet planning actually uses.
Why does sex change the result?
Because average body composition differs, the Mifflin-St Jeor formula uses a different constant for men and women, producing a different baseline. It is a population-level adjustment, not a judgment; the result is an estimate that individual variation can shift.
Is BMR a good diet target?
No — it is the minimum, not a goal. Eating at BMR long term is unsustainable because it excludes all activity. Use it as the floor and build up with your movement to find a realistic intake for losing, holding, or gaining weight.
How accurate is BMR Calculator?
BMR Calculator uses the same arithmetic your operating system and spreadsheet use, so the result is as precise as the numbers you enter. It does not round or estimate unless a field is explicitly a rounded display value, and you can recompute any time to double-check.
Is my data sent to a server when I use BMR Calculator?
No. BMR Calculator runs completely inside your browser. Anything you type, paste, or upload stays on your device and is never transmitted to a server, stored in a database, or shared with a third party. You can even use it offline once the page has loaded, and closing the tab erases the session.
Does BMR Calculator work on phones and tablets?
Yes. The layout is fully responsive, so BMR Calculator behaves the same on a phone, tablet, or desktop — the form reflows to fit the screen and the buttons stay easy to tap. There is no app to install; just open the page in any modern browser and it works.
Is BMR Calculator free, and do I need an account?
BMR Calculator is free to use with no account, no sign-up, and no usage limits. It is part of toolpermarket, a matrix of private, browser-based utilities built for everyday tasks, so you can return as often as you like without registering.