BMR計算機
安静時に消費する基礎代謝量を計算します
What is BMR and why does it matter?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain vital functions like breathing and circulation. It accounts for 60-75% of your total daily calorie burn. Knowing your BMR helps you calculate accurate calorie targets for weight loss, maintenance, or muscle gain.
Get Your Personalized Workout Plan
Turn your calculator results into action. Sign up for free to get AI-powered workout plans tailored to your body metrics and fitness goals.
Create Free AccountBMRとは？
BMR（基礎代謝量）は、何もしなくても体が消費するカロリーのことです。呼吸、血液循環、体温調節など、生きているだけで使われるエネルギー量を指します。1日の総消費カロリーの60〜75%を占めるため、ダイエットや増量を考える上での基本となる数値です。
計算式の違い
代表的な計算式として、Mifflin-St Jeor式とHarris-Benedict式があります。Mifflin-St Jeor式（1990年発表）は現代人に対してより正確とされています。Harris-Benedict式（1918年発表）はやや高めに出る傾向がありますが、医療現場では今でもよく使われています。
BMRに影響する要素
年齢・体重・身長・性別のほかにも、さまざまな要因がBMRに影響します。筋肉量が多いほどBMRは高くなります（筋肉は脂肪よりも多くのカロリーを消費）。ホルモンバランス、体温、ストレス、遺伝なども関係します。急激なダイエットはBMRを下げてしまうので、無理のない食事管理を心がけましょう。
BMR vs TDEE: Understanding the Difference
BMR is your resting calorie burn — what your body needs just to survive. TDEE adds your daily activity on top of BMR. Think of BMR as your body's idle fuel consumption and TDEE as total fuel including driving. Never eat below your BMR; use TDEE to set your daily calorie target.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest just to maintain basic functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) includes your BMR plus calories burned through physical activity, digestion, and daily movement. TDEE is always higher than BMR.
Which BMR formula is most accurate?
The Mifflin-St Jeor equation is considered the most accurate BMR formula for most people, as confirmed by the American Dietetic Association. It was developed in 1990 using modern population data and tends to be more reliable than the older Harris-Benedict equation.
Can I eat below my BMR to lose weight faster?
Eating below your BMR is generally not recommended. Your BMR represents the minimum energy your body needs for basic functions. Consuming fewer calories can slow your metabolism, cause muscle loss, and lead to nutritional deficiencies. Aim to eat between your BMR and TDEE for healthy weight loss.
How can I increase my BMR?
The most effective way to increase your BMR is by building muscle mass through strength training, as muscle tissue burns more calories at rest than fat tissue. Staying hydrated, getting adequate sleep, eating enough protein, and avoiding crash diets also help maintain a healthy metabolic rate.
Does BMR change with age?
Yes, BMR typically decreases by about 1-2% per decade after age 20, primarily due to loss of muscle mass and hormonal changes. Regular strength training and maintaining muscle mass can help counteract this age-related decline in metabolic rate.