Use this precise bmr for weight loss calculator to estimate basal metabolic rate, daily maintenance calories, and a sustainable calorie deficit for effective fat loss.
Instant bmr for weight loss calculator
Enter current body weight in kilograms.
Standing height in centimeters.
Age impacts resting calorie burn.
Male
Female
Mifflin St Jeor factors differ by sex.
Sedentary (little exercise)
Light (1-3 days/week)
Moderate (3-5 days/week)
Active (6-7 days/week)
Very Active (physical job)
Multiplier for maintenance calories.
Typical safe range is 300-750 kcal/day.
Target calories for weight loss: 0 kcal/day
BMR (Resting burn):0 kcal/day
Maintenance calories:0 kcal/day
Estimated weekly loss:0.00 kg/week
Minimum safe intake check:Review inputs
Formula: Mifflin St Jeor — For men: (10 × weight kg) + (6.25 × height cm) − (5 × age years) + 5. For women: (10 × weight kg) + (6.25 × height cm) − (5 × age years) − 161. Maintenance = BMR × activity factor. Target weight-loss calories = maintenance − chosen deficit.
Maintenance calories
Target weight-loss calories
Chart: Weekly view comparing maintenance energy needs versus calorie deficit targets.
Metric
Value
Meaning
Basal Metabolic Rate
0 kcal/day
Calories burned at rest
Maintenance Calories
0 kcal/day
Calories to maintain weight
Daily Deficit
0 kcal/day
Shortfall to drive fat loss
Weekly Loss Projection
0.00 kg/week
Approximate fat reduction
Minimum Safe Intake
Review inputs
Ensures not too low intake
Table: bmr for weight loss calculator outputs summarizing daily and weekly calorie projections.
What is bmr for weight loss calculator?
The bmr for weight loss calculator estimates basal metabolic rate to show how many calories your body burns at rest and how to create a calorie deficit for fat loss. People pursuing fat reduction, performance nutrition, and metabolic health use a bmr for weight loss calculator to set realistic intake targets. A bmr for weight loss calculator also corrects misconceptions such as thinking all calorie deficits are equal or that crash dieting accelerates lasting results.
A bmr for weight loss calculator focuses on individualized factors like sex, age, height, weight, and activity so you avoid generic numbers. Athletes, office workers, and postpartum clients can all apply a bmr for weight loss calculator to align energy intake with sustainable weight change.
bmr for weight loss calculator Formula and Mathematical Explanation
The bmr for weight loss calculator uses the Mifflin St Jeor equation because it balances accuracy and practicality. Step one multiplies weight by ten to anchor metabolic cost of mass. Step two multiplies height by 6.25 to account for lean tissue surface area. Step three subtracts five times age to reflect slowing metabolic pace. Finally, the sex constant (+5 for men, −161 for women) adjusts for hormonal and body composition differences.
Maintenance calories equal BMR multiplied by an activity factor between 1.2 and 1.9. The bmr for weight loss calculator subtracts a chosen deficit to target fat loss while keeping intake above a safe floor (often no lower than 1200–1500 kcal for most adults, depending on build). Weekly fat loss is deficit × 7 ÷ 7700 because about 7700 kcal approximate one kilogram of body fat.
Variable
Meaning
Unit
Typical Range
BMR
Basal Metabolic Rate
kcal/day
1200–2300
Weight
Body mass
kg
45–130
Height
Stature
cm
150–200
Age
Chronological age
years
18–70
Activity
Lifestyle factor
multiplier
1.2–1.9
Deficit
Calorie shortfall
kcal/day
300–750
Variables the bmr for weight loss calculator applies to compute personalized calorie guidance.
Practical Examples (Real-World Use Cases)
Example 1: Desk professional starting gym routine
Inputs: weight 78 kg, height 180 cm, age 34, male, moderate activity 1.55, deficit 500. The bmr for weight loss calculator returns BMR ≈ 1757 kcal, maintenance ≈ 2724 kcal, and a target intake near 2224 kcal. Weekly loss projects to about 0.45 kg, signaling steady fat reduction without extreme hunger.
Example 2: Busy parent prioritizing gentle deficit
Inputs: weight 64 kg, height 165 cm, age 38, female, light activity 1.375, deficit 350. The bmr for weight loss calculator shows BMR ≈ 1373 kcal, maintenance ≈ 1887 kcal, and target intake ≈ 1537 kcal. Expected weekly loss is roughly 0.32 kg, balancing energy for family demands and gradual progress.
How to Use This bmr for weight loss calculator
Enter weight, height, age, and select sex so the bmr for weight loss calculator sets your baseline. Choose your activity level for an accurate maintenance multiplier. Pick a daily deficit that feels sustainable. Review the primary target calories and intermediate numbers for BMR, maintenance, and projected weekly loss. Adjust the deficit if the minimum safe intake warning appears; the bmr for weight loss calculator keeps you above overly low intakes.
Read the chart to compare maintenance versus target intake over a week. Use the table to log numbers into your meal planner or nutrition tracker. Copy results for quick sharing with a coach or clinician.
Key Factors That Affect bmr for weight loss calculator Results
Age: Each decade can lower BMR; the bmr for weight loss calculator accounts for metabolic shifts.
Lean mass: More muscle raises BMR, so resistance training can change future outputs.
Activity multiplier: Underestimating movement inflates deficit; overestimating shrinks it.
Deficit size: Large deficits may reduce adherence and metabolic efficiency; moderate deficits keep losses steady.
Hormones and sleep: Poor sleep can depress BMR and appetite control, altering calculator accuracy.
Adaptive thermogenesis: Prolonged dieting may slightly reduce BMR; periodic re-evaluation keeps the bmr for weight loss calculator aligned.
Medical factors: Thyroid and medications can shift calorie needs, so inputs may need clinician review.
Macronutrient balance: Protein intake supports muscle, stabilizing BMR while in deficit.
Frequently Asked Questions (FAQ)
Does the bmr for weight loss calculator work for athletes? Yes, select a higher activity factor to reflect training volume.
How often should I recalc? Revisit the bmr for weight loss calculator every 4–6 weeks or after a 3–5 kg change.
Is the deficit safe? Aim for 300–750 kcal; the calculator flags overly low targets.
Why is my target above BMR? Intakes below BMR can harm recovery; the bmr for weight loss calculator maintains safety.
Can I use pounds and inches? Convert to kilograms and centimeters for best accuracy.
Does strength training change numbers? More muscle can raise BMR; update the bmr for weight loss calculator after gains.
What if I plateau? Reassess activity accuracy, adjust deficit slightly, and verify logging consistency.
Can pregnant individuals use this? Pregnancy alters needs; seek medical guidance instead of relying solely on a bmr for weight loss calculator.
Related Tools and Internal Resources
Calorie deficit planner – Pair with the bmr for weight loss calculator to balance nutrition.
TDEE calculator – Compare activity multipliers against the bmr for weight loss calculator output.
Protein intake guide – Safeguard muscle while using the bmr for weight loss calculator.
Weight loss planner – Map timelines using the weekly loss from this calculator.
var defaultValues={
weightKg:70,
heightCm:175,
ageYears:30,
gender:"male",
activity:"1.55″,
deficit:500
};
function validNumber(value,min,max){
if(isNaN(value)){return false;}
if(valuemax){return false;}
return true;
}
function setError(id,msg){
var el=document.getElementById(id);
el.innerText=msg;
}
function resetForm(){
document.getElementById("weightKg").value=defaultValues.weightKg;
document.getElementById("heightCm").value=defaultValues.heightCm;
document.getElementById("ageYears").value=defaultValues.ageYears;
document.getElementById("gender").value=defaultValues.gender;
document.getElementById("activity").value=defaultValues.activity;
document.getElementById("deficit").value=defaultValues.deficit;
calculateBMR();
}
function calculateBMR(){
var weight=parseFloat(document.getElementById("weightKg").value);
var height=parseFloat(document.getElementById("heightCm").value);
var age=parseInt(document.getElementById("ageYears").value,10);
var gender=document.getElementById("gender").value;
var activity=parseFloat(document.getElementById("activity").value);
var deficit=parseFloat(document.getElementById("deficit").value);
var ok=true;
if(!validNumber(weight,30,250)){setError("weightKgError","Enter weight between 30 and 250 kg.");ok=false;}else{setError("weightKgError","");}
if(!validNumber(height,120,230)){setError("heightCmError","Enter height between 120 and 230 cm.");ok=false;}else{setError("heightCmError","");}
if(!validNumber(age,15,90)){setError("ageYearsError","Enter age between 15 and 90.");ok=false;}else{setError("ageYearsError","");}
if(!activity){setError("activityError","Select an activity level.");ok=false;}else{setError("activityError","");}
if(!validNumber(deficit,100,1500)){setError("deficitError","Enter deficit between 100 and 1500 kcal.");ok=false;}else{setError("deficitError","");}
if(!ok){return;}
var bmr=0;
if(gender==="male"){
bmr=(10*weight)+(6.25*height)-(5*age)+5;
}else{
bmr=(10*weight)+(6.25*height)-(5*age)-161;
}
var maintenance=bmr*activity;
var target=maintenance-deficit;
if(target<1000){target=1000;}
var weeklyLoss=(deficit*7)/7700;
var safetyMessage="";
if(target<1200 && gender==="female"){safetyMessage="Below common safe intake; consider smaller deficit.";}
else if(target<1500 && gender==="male"){safetyMessage="Below common safe intake; consider smaller deficit.";}
else{safetyMessage="Within typical safe range for most adults.";}
document.getElementById("primaryResult").innerText="Target calories for weight loss: "+Math.round(target)+" kcal/day";
document.getElementById("bmrValue").innerText=Math.round(bmr)+" kcal/day";
document.getElementById("maintenanceValue").innerText=Math.round(maintenance)+" kcal/day";
document.getElementById("weeklyLossValue").innerText=weeklyLoss.toFixed(2)+" kg/week";
document.getElementById("safetyCheck").innerText=safetyMessage;
document.getElementById("tableBmr").innerText=Math.round(bmr)+" kcal/day";
document.getElementById("tableMaintenance").innerText=Math.round(maintenance)+" kcal/day";
document.getElementById("tableDeficit").innerText=Math.round(deficit)+" kcal/day";
document.getElementById("tableWeeklyLoss").innerText=weeklyLoss.toFixed(2)+" kg/week";
document.getElementById("tableSafety").innerText=safetyMessage;
drawChart(maintenance,target);
}
function copyResults(){
var text="bmr for weight loss calculator results:\n";
text+="BMR: "+document.getElementById("bmrValue").innerText+"\n";
text+="Maintenance: "+document.getElementById("maintenanceValue").innerText+"\n";
text+="Target intake: "+document.getElementById("primaryResult").innerText.replace("Target calories for weight loss: ","")+"\n";
text+="Estimated weekly loss: "+document.getElementById("weeklyLossValue").innerText+"\n";
text+="Safety note: "+document.getElementById("safetyCheck").innerText;
if(navigator.clipboard&&navigator.clipboard.writeText){
navigator.clipboard.writeText(text);
}else{
var temp=document.createElement("textarea");
temp.value=text;
document.body.appendChild(temp);
temp.select();
document.execCommand("copy");
document.body.removeChild(temp);
}
}
function drawChart(maintenance,target){
var canvas=document.getElementById("calorieChart");
var ctx=canvas.getContext("2d");
ctx.clearRect(0,0,canvas.width,canvas.height);
var padding=50;
var width=canvas.width-padding*2;
var height=canvas.height-padding*2;
var days=["Mon","Tue","Wed","Thu","Fri","Sat","Sun"];
var maintenanceData=[];
var targetData=[];
var i;
for(i=0;i<7;i++){
maintenanceData.push(maintenance);
targetData.push(target);
}
var maxVal=Math.max(maintenance,target);
var minVal=Math.min(target,maintenance);
if(maxVal===minVal){maxVal=minVal+100;}
ctx.strokeStyle="#e0e6f0";
ctx.lineWidth=1;
var y;
for(i=0;i<=5;i++){
y=padding+(height/5*i);
ctx.beginPath();
ctx.moveTo(padding,y);
ctx.lineTo(padding+width,y);
ctx.stroke();
}
ctx.fillStyle="#1f2a3d";
ctx.font="13px Arial";
ctx.textAlign="center";
for(i=0;i<7;i++){
var x=padding+(width/6*i);
ctx.fillText(days[i],x,height+padding+18);
}
function plotLine(data,color){
ctx.strokeStyle=color;
ctx.lineWidth=3;
ctx.beginPath();
for(i=0;i<data.length;i++){
var val=data[i];
var x=padding+(width/6*i);
var ratio=(val-minVal)/(maxVal-minVal);
var yPos=padding+height-(ratio*height);
if(i===0){ctx.moveTo(x,yPos);}else{ctx.lineTo(x,yPos);}
}
ctx.stroke();
}
plotLine(maintenanceData,"#004a99");
plotLine(targetData,"#28a745");
ctx.fillStyle="#1f2a3d";
ctx.textAlign="right";
ctx.fillText(Math.round(maxVal)+" kcal",padding-6,padding+6);
ctx.fillText(Math.round(minVal)+" kcal",padding-6,height+padding);
}
calculateBMR();