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BMI and TDEE calculator

Your BMI with its category, and an estimate of your daily calorie needs via the Mifflin St Jeor equation. Metric or imperial including stones, nothing typed here leaves your browser.

Last checked 3 Nov 2026

Please complete every field with realistic values.

Your BMI--
Resting rate (BMR)-kcal per day at complete rest
Maintenance (TDEE)-kcal per day at your activity level

Reading the results

BMI is a screening measure, not a verdict: it cannot see muscle, frame or body composition, and UK guidance applies lower risk thresholds for several ethnic backgrounds, all covered on the BMI requirements page along with the licensed treatment thresholds. TDEE is a population estimate of daily calorie use. Sustainable weight loss usually works with a moderate deficit under professional guidance rather than aggressive cuts, and the consultation guide explains how providers assess the full picture. Providers always verify height and weight themselves, so use this tool as a guide, not as part of any application.

Independence note: iGovy does not sell, prescribe or dispense medicines, and this calculator is general information, not medical advice or a diagnosis. Results are estimates. Decisions about treatment or significant calorie changes belong with a qualified professional.

Calculator questions

What is TDEE?

Total daily energy expenditure: an estimate of the calories your body uses per day, combining your resting metabolic rate with your activity level. This tool estimates resting rate with the Mifflin St Jeor equation and multiplies by a standard activity factor.

How accurate are these numbers?

They are population estimates, useful for orientation rather than prescription. Muscle mass, medical conditions and medicines all shift real needs, and BMI has known limits for very muscular or older bodies. Treat results as a starting point for a professional conversation.

Does my BMI here decide treatment eligibility?

No. UK providers verify height and weight themselves and a prescriber weighs your full history. The licensed thresholds and the ethnicity adjustments in UK guidance are explained on the BMI requirements page.

Is my data stored?

No. The calculator runs entirely in your browser on this page. Nothing you type is sent to iGovy or anyone else.

Sources referenced on this page

Standing primary references for every iGovy page: