Use this dedicated weighted average life calculation in excel tool to map principal repayments over time, compute weighted average life instantly, and understand how repayment timing shifts portfolio risk. Inputs update results in real time so you can mirror the exact weighted average life calculation in excel without manual formulas.
Weighted Average Life Calculation in Excel Calculator
Enter principal repayments and the months until each repayment to replicate weighted average life calculation in excel with immediate visualization.
Sum of all principal outstanding before repayments
Controls how many repayment rows are active in the weighted average life calculation in excel
Principal repaid in period 1
Months until repayment 1 occurs
Principal repaid in period 2
Months until repayment 2 occurs
Principal repaid in period 3
Months until repayment 3 occurs
Principal repaid in period 4
Months until repayment 4 occurs
Principal repaid in period 5
Months until repayment 5 occurs
Principal repaid in period 6
Months until repayment 6 occurs
Weighted Average Life (years)
0.00 years
Formula: WAL = Σ(Principal Repayment × Time in Years) / Total Principal
Total principal analyzed: 0
Weighted principal-time (month-units): 0
Weighted average life (months): 0
Final maturity (latest month): 0
Repayment schedule used for weighted average life calculation in excel
Period
Principal
Timing (months)
Weighted Contribution
Blue bars: principal per period | Green line: cumulative principal repaid (%)
Chart visualizing principal timing for weighted average life calculation in excel
What is weighted average life calculation in excel?
Weighted average life calculation in excel measures how long, on average, principal remains outstanding before being repaid. Investors, treasury teams, and structured finance analysts use weighted average life calculation in excel to compare bonds, mortgage pools, and amortizing assets. A common misconception is that weighted average life calculation in excel equals final maturity; instead, it is a repayment-weighted time that is often much shorter than the last cash flow.
Another misconception is that weighted average life calculation in excel ignores prepayments. In reality, every shift in principal timing changes weighted average life calculation in excel, so incorporating expected prepayments is essential.
weighted average life calculation in excel Formula and Mathematical Explanation
The weighted average life calculation in excel formula multiplies each principal repayment by its time, sums those products, and divides by total principal. In spreadsheet terms, weighted average life calculation in excel is Σ(Principal_i × Time_i) / ΣPrincipal_i, where Time_i is usually measured in years as Months_i / 12.
Derivation: start with the concept of an average holding period weighted by cash magnitude. The numerator captures time exposure of each dollar; the denominator normalizes to total principal. This yields the weighted average life calculation in excel that aligns with bond math and amortization logic.
Variables for weighted average life calculation in excel
Inputs: total principal 500000; repayments: 120000 in month 6, 180000 in month 12, 200000 in month 24. Weighted average life calculation in excel gives around 1.33 years. Interpretation: principal comes back quickly, reducing duration risk.
Example 2: Mortgage pool with prepayments
Inputs: total principal 750000; repayments: 100000 in month 3, 150000 in month 6, 200000 in month 12, 150000 in month 18, 150000 in month 24. Weighted average life calculation in excel is roughly 1.29 years. Interpretation: accelerated prepayments shorten weighted average life calculation in excel, lowering exposure to credit spread moves.
How to Use This weighted average life calculation in excel Calculator
Enter total principal and choose 3-6 repayment rows to mirror your dataset.
Input each repayment amount and the months until it occurs.
Watch the weighted average life calculation in excel update instantly in years and months.
Review the table and chart to confirm timing distribution.
Use Copy Results to paste weighted average life calculation in excel outputs into models.
Reading results: the highlighted years value is the weighted average life calculation in excel; months show finer granularity. If weighted average life calculation in excel declines after you accelerate a cash flow, risk is decreasing.
Does weighted average life calculation in excel equal duration? No, duration includes discounting and interest; weighted average life calculation in excel focuses on principal timing.
Can I use days instead of months? Yes, but convert consistently so weighted average life calculation in excel stays comparable.
How does prepayment modeling impact weighted average life calculation in excel? Faster speeds lower weighted average life calculation in excel because cash returns sooner.
Is weighted average life calculation in excel affected by coupons? Only principal matters; interest does not change weighted average life calculation in excel.
What if total repayments differ from total principal? Normalize to the actual principal for accurate weighted average life calculation in excel.
Can negative months occur? No, negative timing invalidates weighted average life calculation in excel; use non-negative values.
How many periods should I use? Use as many as needed to represent distinct repayments; the weighted average life calculation in excel here supports up to six.
How do balloon payments show up? They create a large weight near maturity, increasing weighted average life calculation in excel.
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{related_keywords} – Internal benchmarks to sanity check weighted average life calculation in excel outputs.
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{related_keywords} – Troubleshooting playbook for weighted average life calculation in excel edge cases.
var defaultPrincipals=[120000,180000,150000,90000,60000,50000];
var defaultMonths=[6,12,18,24,30,36];
function setDefaultWAL(){
document.getElementById("totalPrincipal").value=650000;
document.getElementById("periodCount").value=5;
var i;
for(i=1;i<=6;i++){
document.getElementById("principal"+i).value=defaultPrincipals[i-1];
document.getElementById("month"+i).value=defaultMonths[i-1];
}
adjustRows();
calculateWAL();
}
function adjustRows(){
var count=parseInt(document.getElementById("periodCount").value,10);
if(isNaN(count)||count6){count=6;}
document.getElementById("periodCount").value=count;
var i;
for(i=1;i<=6;i++){
var display=i<=count?"block":"none";
document.getElementById("principal"+i).parentNode.style.display=display;
document.getElementById("month"+i).parentNode.style.display=display;
}
calculateWAL();
}
function calculateWAL(){
var totalPrincipalInput=parseFloat(document.getElementById("totalPrincipal").value);
var periodCount=parseInt(document.getElementById("periodCount").value,10);
var valid=true;
if(isNaN(totalPrincipalInput)||totalPrincipalInput<=0){
document.getElementById("error-totalPrincipal").innerHTML="Enter a positive total principal.";
valid=false;
}else{
document.getElementById("error-totalPrincipal").innerHTML="";
}
if(isNaN(periodCount)||periodCount6){
document.getElementById("error-periodCount").innerHTML="Use 3 to 6 repayment entries.";
valid=false;
}else{
document.getElementById("error-periodCount").innerHTML="";
}
var totalsum=0;
var weightedSum=0;
var maxMonth=0;
var scheduleHTML="";
var i;
for(i=1;i<=6;i++){
var principalVal=parseFloat(document.getElementById("principal"+i).value);
var monthVal=parseFloat(document.getElementById("month"+i).value);
var errPrincipal=document.getElementById("error-principal"+i);
var errMonth=document.getElementById("error-month"+i);
if(i<=periodCount){
if(isNaN(principalVal)||principalVal<0){
errPrincipal.innerHTML="Enter a non-negative principal.";
valid=false;
}else{errPrincipal.innerHTML="";}
if(isNaN(monthVal)||monthVal0&&!isNaN(monthVal)&&monthVal>=0){
totalsum+=principalVal;
weightedSum+=principalVal*(monthVal/12);
if(monthVal>maxMonth){maxMonth=monthVal;}
scheduleHTML+="
Period "+i+"
"+principalVal.toFixed(2)+"
"+monthVal.toFixed(0)+"
"+(principalVal*(monthVal/12)).toFixed(2)+"
";
}
}else{
errPrincipal.innerHTML="";
errMonth.innerHTML="";
}
}
document.getElementById("schedule-body").innerHTML=scheduleHTML;
if(!valid||totalsum<=0){
document.getElementById("walResult").innerHTML="0.00 years";
document.getElementById("intermediate-total").innerHTML="Total principal analyzed: 0";
document.getElementById("intermediate-weighted").innerHTML="Weighted principal-time (month-units): 0";
document.getElementById("intermediate-months").innerHTML="Weighted average life (months): 0";
document.getElementById("intermediate-maxmonth").innerHTML="Final maturity (latest month): 0";
drawChart([],[],0);
return;
}
var walYears=weightedSum/totalsum;
var walMonths=walYears*12;
document.getElementById("walResult").innerHTML=walYears.toFixed(2)+" years";
document.getElementById("intermediate-total").innerHTML="Total principal analyzed: "+totalsum.toFixed(2);
document.getElementById("intermediate-weighted").innerHTML="Weighted principal-time (month-units): "+(weightedSum*12).toFixed(2);
document.getElementById("intermediate-months").innerHTML="Weighted average life (months): "+walMonths.toFixed(2);
document.getElementById("intermediate-maxmonth").innerHTML="Final maturity (latest month): "+maxMonth.toFixed(0);
updateChartData(periodCount);
}
function updateChartData(periodCount){
var principalData=[];
var monthsData=[];
var i;
for(i=1;i<=periodCount;i++){
var p=parseFloat(document.getElementById("principal"+i).value);
var m=parseFloat(document.getElementById("month"+i).value);
if(isNaN(p)||p<0){p=0;}
if(isNaN(m)||m<0){m=0;}
principalData.push(p);
monthsData.push(m);
}
drawChart(principalData,monthsData,periodCount);
}
function drawChart(principalData,monthsData,count){
var canvas=document.getElementById("walChart");
var ctx=canvas.getContext("2d");
ctx.clearRect(0,0,canvas.width,canvas.height);
ctx.fillStyle="#ffffff";
ctx.fillRect(0,0,canvas.width,canvas.height);
if(!principalData||principalData.length===0){return;}
var maxPrincipal=0;
var i;
for(i=0;imaxPrincipal){maxPrincipal=principalData[i];}}
if(maxPrincipal===0){maxPrincipal=1;}
var chartHeight=240;
var chartWidth=760;
var originX=40;
var originY=280;
var barWidth=chartWidth/(count*1.6);
ctx.strokeStyle="#6c757d";
ctx.beginPath();
ctx.moveTo(originX,40);
ctx.lineTo(originX,originY);
ctx.lineTo(originX+chartWidth,originY);
ctx.stroke();
var cumulative=0;
var total=0;
for(i=0;i<count;i++){total+=principalData[i];}
var cumulativePoints=[];
for(i=0;i0?(cumulative/total)*100:0;
var pointY=originY-(cumPercent/100)*chartHeight;
cumulativePoints.push({x:barX+barWidth/2,y:pointY});
}
ctx.strokeStyle="#28a745″;
ctx.lineWidth=2;
ctx.beginPath();
for(i=0;i<cumulativePoints.length;i++){
if(i===0){ctx.moveTo(cumulativePoints[i].x,cumulativePoints[i].y);}
else{ctx.lineTo(cumulativePoints[i].x,cumulativePoints[i].y);}
}
ctx.stroke();
ctx.fillStyle="#28a745";
for(i=0;i<cumulativePoints.length;i++){
ctx.beginPath();
ctx.arc(cumulativePoints[i].x,cumulativePoints[i].y,3,0,Math.PI*2);
ctx.fill();
}
ctx.fillStyle="#1a1a1a";
ctx.font="10px Arial";
ctx.fillText("0%",10,originY);
ctx.fillText("50%",6,originY-chartHeight/2);
ctx.fillText("100%",6,originY-chartHeight);
}
function copyResults(){
var main=document.getElementById("walResult").innerText;
var t=document.getElementById("intermediate-total").innerText;
var w=document.getElementById("intermediate-weighted").innerText;
var m=document.getElementById("intermediate-months").innerText;
var f=document.getElementById("intermediate-maxmonth").innerText;
var text="Weighted average life calculation in excel results:\n"+main+"\n"+t+"\n"+w+"\n"+m+"\n"+f;
var temp=document.createElement("textarea");
temp.value=text;
document.body.appendChild(temp);
temp.select();
document.execCommand("copy");
document.body.removeChild(temp);
}