{primary_keyword} | calorie deficit to lose weight calculator
Use this calorie deficit to lose weight calculator to estimate maintenance calories, set a safe deficit, and project weekly progress. It updates in real time and explains the math behind {primary_keyword}.
Calorie Deficit to Lose Weight Calculator
Age affects basal metabolism.
Male
Female
Used in the Mifflin-St Jeor equation.
Height shapes resting energy expenditure.
Your starting point for {primary_keyword}.
Goal weight to align the calorie deficit to lose weight calculator.
Longer timelines need smaller daily deficits.
Sedentary (little exercise)
Lightly active (1-3 days/week)
Moderately active (3-5 days/week)
Very active (6-7 days/week)
Athlete (2x per day)
Adjusts BMR to TDEE in the calorie deficit to lose weight calculator.
Adds a buffer to keep deficits sustainable.
Daily calorie target: 0 kcal
Formula: (BMR × Activity) – Required Deficit
BMR (Mifflin-St Jeor)
0 kcal/day
TDEE (Maintenance)
0 kcal/day
Required Daily Deficit
0 kcal/day
Projected Weekly Loss
0 kg/week
Week
Maintenance kcal
Goal kcal
Cumulative Loss (kg)
Projection based on current {primary_keyword} settings
Maintenance (TDEE)
Goal calories
What is {primary_keyword}?
{primary_keyword} is the process of setting a daily calorie target below your total daily energy expenditure to create a consistent energy gap that drives fat loss. People who want structured, predictable weight reduction rely on {primary_keyword} to quantify maintenance calories and the deficit needed to reach a goal weight on schedule.
The {primary_keyword} method suits individuals who prefer data-driven nutrition, athletes planning weight classes, and anyone seeking a safe, sustainable path to reduce body fat. A common misconception about {primary_keyword} is that deeper deficits always speed results; in reality, aggressive cuts often reduce lean mass and compliance, making the {primary_keyword} calculator crucial for balance.
Another misconception is that {primary_keyword} ignores activity. The calorie deficit to lose weight calculator scales BMR by activity to reflect real-world energy needs, keeping {primary_keyword} aligned with training and daily movement.
See guidance and context via {related_keywords} for additional reading on {primary_keyword} planning.
{primary_keyword} Formula and Mathematical Explanation
The core of {primary_keyword} combines resting metabolism, activity, and energy density of body fat to find a daily calorie target that closes the gap to your goal weight over a chosen timeframe.
Step-by-step {primary_keyword} math:
BMR (Mifflin-St Jeor): for males = 10×weight(kg) + 6.25×height(cm) – 5×age + 5; for females subtract 161 instead of adding 5.
TDEE = BMR × activity factor (1.2–1.9) to capture movement in {primary_keyword}.
Goal loss (kg) = current weight – target weight.
Energy needed = goal loss × 7700 kcal per kg of body fat.
Daily deficit = Energy needed ÷ (weeks × 7); {primary_keyword} uses this to size the gap.
Total daily energy expenditure in {primary_keyword}
kcal/day
1500 – 3500
Goal loss
Current minus target weight
kg
2 – 30
Daily deficit
Energy gap for {primary_keyword}
kcal/day
250 – 1000
Calorie target
Maintenance minus deficit
kcal/day
1200 – 2800
Key variables powering the {primary_keyword} calculator
For further context on safe energy targets, review {related_keywords} which aligns with the principles of {primary_keyword}.
Practical Examples (Real-World Use Cases)
Example 1: Gradual cut for an office professional
Inputs: age 32, female, 165 cm, 72 kg current, 65 kg target, 16 weeks, lightly active. The {primary_keyword} calculator finds BMR ≈ 1485 kcal, TDEE ≈ 2040 kcal, daily deficit ≈ 305 kcal, and calorie target ≈ 1735 kcal. Interpretation: a modest gap preserves energy for work while achieving roughly 0.4 kg loss per week.
This {primary_keyword} approach mirrors recommendations in {related_keywords} to prioritize adherence.
Example 2: Athlete trimming for competition
Inputs: age 27, male, 178 cm, 82 kg current, 75 kg target, 8 weeks, very active. The {primary_keyword} calculator returns BMR ≈ 1790 kcal, TDEE ≈ 3080 kcal, daily deficit ≈ 675 kcal, and calorie target ≈ 2405 kcal. Interpretation: an aggressive but manageable cut with adequate fuel for training.
See {related_keywords} to align training loads with {primary_keyword} nutrition.
How to Use This {primary_keyword} Calculator
Enter age, sex, height, and current weight to anchor BMR.
Set your target weight and timeframe so the {primary_keyword} tool sizes the deficit.
Select activity level to adjust for movement.
Use diet intensity cushion to soften the deficit if adherence is a concern.
Review the main calorie target and intermediate values for {primary_keyword} clarity.
Copy results to share with a coach or log your plan.
When reading results, focus on daily calorie target and daily deficit. If the target is below 1200 kcal for women or 1500 kcal for men, consider extending the timeframe. This keeps {primary_keyword} sustainable.
Bookmark {related_keywords} to revisit your {primary_keyword} plan as activity shifts.
{related_keywords} – newsletter to stay updated on {primary_keyword} research.
function calculate(){
var age=parseFloat(document.getElementById("age").value);
var gender=document.getElementById("gender").value;
var height=parseFloat(document.getElementById("height").value);
var currentWeight=parseFloat(document.getElementById("currentWeight").value);
var targetWeight=parseFloat(document.getElementById("targetWeight").value);
var timeframe=parseFloat(document.getElementById("timeframe").value);
var activityLevel=parseFloat(document.getElementById("activityLevel").value);
var dietIntensity=parseFloat(document.getElementById("dietIntensity").value);
var valid=true;
valid=validateNumber("age",age,10,100)&&valid;
valid=validateSelect("gender",gender)&&valid;
valid=validateNumber("height",height,120,230)&&valid;
valid=validateNumber("currentWeight",currentWeight,40,250)&&valid;
valid=validateNumber("targetWeight",targetWeight,35,200)&&valid;
valid=validateNumber("timeframe",timeframe,2,52)&&valid;
valid=validateSelect("activityLevel",activityLevel)&&valid;
valid=validateNumber("dietIntensity",dietIntensity,0,30)&&valid;
if(!valid){return;}
if(targetWeight>=currentWeight){document.getElementById("error-targetWeight").innerHTML="Target weight must be lower than current weight for a deficit.";return;}else{document.getElementById("error-targetWeight").innerHTML="";}
var bmr=0;
if(gender==="male"){bmr=10*currentWeight+6.25*height-5*age+5;}else{bmr=10*currentWeight+6.25*height-5*age-161;}
var tdee=bmr*activityLevel;
var totalLoss=currentWeight-targetWeight;
var energyNeed=totalLoss*7700;
var dailyDeficit=energyNeed/(timeframe*7);
var cushion=(dietIntensity/100)*dailyDeficit;
var adjustedDeficit=Math.max(dailyDeficit-cushion,0);
var calorieTarget=Math.max(tdee-adjustedDeficit,1200);
var weeklyLoss=adjustedDeficit*7/7700;
document.getElementById("bmrValue").innerHTML=Math.round(bmr)+" kcal/day";
document.getElementById("tdeeValue").innerHTML=Math.round(tdee)+" kcal/day";
document.getElementById("deficitValue").innerHTML=Math.round(adjustedDeficit)+" kcal/day";
document.getElementById("weeklyLossValue").innerHTML=weeklyLoss.toFixed(2)+" kg/week";
document.getElementById("mainResult").innerHTML="Daily calorie target: "+Math.round(calorieTarget)+" kcal";
document.getElementById("formulaText").innerHTML="Formula: (BMR × Activity) – Daily Deficit + Cushion";
buildTable(tdee,calorieTarget,weeklyLoss,timeframe);
drawChart(tdee,calorieTarget,timeframe);
}
function validateNumber(id,value,min,max){
var error=document.getElementById("error-"+id);
if(isNaN(value)){error.innerHTML="Please enter a number.";return false;}
if(valuemax){error.innerHTML="Value must be between "+min+" and "+max+".";return false;}
error.innerHTML="";return true;
}
function validateSelect(id,value){
var error=document.getElementById("error-"+id);
if(value===undefined||value===""||value===null){error.innerHTML="Please select an option.";return false;}
error.innerHTML="";return true;
}
function resetCalc(){
document.getElementById("age").value=30;
document.getElementById("gender").value="male";
document.getElementById("height").value=175;
document.getElementById("currentWeight").value=80;
document.getElementById("targetWeight").value=72;
document.getElementById("timeframe").value=12;
document.getElementById("activityLevel").value="1.375″;
document.getElementById("dietIntensity").value=10;
var errors=document.querySelectorAll(".error");
for(var i=0;i<errors.length;i++){errors[i].innerHTML="";}
calculate();
}
function copyResults(){
var text="calorie deficit to lose weight calculator results:\n";
text+="Main target: "+document.getElementById("mainResult").innerText+"\n";
text+="BMR: "+document.getElementById("bmrValue").innerText+"\n";
text+="TDEE: "+document.getElementById("tdeeValue").innerText+"\n";
text+="Daily deficit: "+document.getElementById("deficitValue").innerText+"\n";
text+="Projected weekly loss: "+document.getElementById("weeklyLossValue").innerText+"\n";
text+="Assumptions: Using {primary_keyword} with activity factor "+document.getElementById("activityLevel").value+" and timeframe "+document.getElementById("timeframe").value+" weeks.";
if(navigator.clipboard&&navigator.clipboard.writeText){navigator.clipboard.writeText(text);}
}
function buildTable(tdee,calorieTarget,weeklyLoss,timeframe){
var tbody=document.getElementById("progressTable");
tbody.innerHTML="";
var cumulative=0;
for(var w=1;w<=timeframe;w++){
cumulative+=weeklyLoss;
var tr=document.createElement("tr");
var cells=[w,Math.round(tdee),Math.round(calorieTarget),cumulative.toFixed(2)];
for(var c=0;c<cells.length;c++){
var td=document.createElement("td");
td.textContent=cells[c];
tr.appendChild(td);
}
tbody.appendChild(tr);
}
}
function drawChart(tdee,calorieTarget,timeframe){
var canvas=document.getElementById("progressChart");
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 maxVal=Math.max(tdee,calorieTarget)*1.1;
if(maxVal<100){maxVal=100;}
ctx.strokeStyle="#c8d4e2";
ctx.lineWidth=1;
ctx.beginPath();
ctx.moveTo(padding,padding);
ctx.lineTo(padding,canvas.height-padding);
ctx.lineTo(canvas.width-padding,canvas.height-padding);
ctx.stroke();
var pointsMaint=[];
var pointsGoal=[];
for(var i=0;i<=timeframe;i++){
var x=padding+(width*(i/timeframe));
var yMaint=canvas.height-padding-(height*(tdee/maxVal));
var yGoal=canvas.height-padding-(height*(calorieTarget/maxVal));
pointsMaint.push({x:x,y:yMaint});
pointsGoal.push({x:x,y:yGoal});
}
ctx.strokeStyle="#004a99";
ctx.lineWidth=2;
ctx.beginPath();
for(var j=0;j<pointsMaint.length;j++){
if(j===0){ctx.moveTo(pointsMaint[j].x,pointsMaint[j].y);}else{ctx.lineTo(pointsMaint[j].x,pointsMaint[j].y);}
}
ctx.stroke();
ctx.strokeStyle="#28a745";
ctx.lineWidth=2;
ctx.beginPath();
for(var k=0;k<pointsGoal.length;k++){
if(k===0){ctx.moveTo(pointsGoal[k].x,pointsGoal[k].y);}else{ctx.lineTo(pointsGoal[k].x,pointsGoal[k].y);}
}
ctx.stroke();
ctx.fillStyle="#004a99";
for(var a=0;a<pointsMaint.length;a++){ctx.beginPath();ctx.arc(pointsMaint[a].x,pointsMaint[a].y,4,0,Math.PI*2);ctx.fill();}
ctx.fillStyle="#28a745";
for(var b=0;b<pointsGoal.length;b++){ctx.beginPath();ctx.arc(pointsGoal[b].x,pointsGoal[b].y,4,0,Math.PI*2);ctx.fill();}
ctx.fillStyle="#1f2a36";
ctx.font="12px Arial";
ctx.fillText("kcal/day",padding-30,padding-10);
ctx.fillText("Weeks",canvas.width-padding-30,canvas.height-padding+30);
ctx.fillText("Chart shows maintenance vs goal calories for {primary_keyword}",padding,canvas.height-10);
}
window.onload=calculate;