Sum of rent, utilities, insurance, depreciation, and indirect labor.
Direct Labor Cost ($)
Direct Labor Hours
Machine Hours
The total amount of the chosen base across the entire company/period.
Step 2: Apply to Specific Job (Optional)
Enter the specific amount used for a single project or product.
Calculation Results
Overhead Rate:–
Rate Formula:–
Allocated Overhead to Job:–
Total Job Cost Impact:–
(Job Base Input + Allocated Overhead)
function updateLabels() {
var type = document.getElementById('baseType').value;
var baseLabel = document.getElementById('baseAmountLabel');
var projectLabel = document.getElementById('projectBaseLabel');
var baseInput = document.getElementById('baseAmount');
var projectInput = document.getElementById('projectBase');
if (type === 'laborCost') {
baseLabel.innerText = "Total Direct Labor Cost ($)";
projectLabel.innerText = "Job Specific Labor Cost ($)";
baseInput.placeholder = "e.g. 20000";
} else if (type === 'laborHours') {
baseLabel.innerText = "Total Direct Labor Hours";
projectLabel.innerText = "Job Specific Labor Hours";
baseInput.placeholder = "e.g. 1000";
} else if (type === 'machineHours') {
baseLabel.innerText = "Total Machine Hours";
projectLabel.innerText = "Job Specific Machine Hours";
baseInput.placeholder = "e.g. 500";
}
}
function calculateOverhead() {
// Get Inputs
var indirect = parseFloat(document.getElementById('indirectCosts').value);
var baseTotal = parseFloat(document.getElementById('baseAmount').value);
var projectVal = parseFloat(document.getElementById('projectBase').value);
var type = document.getElementById('baseType').value;
// Validation
if (isNaN(indirect) || isNaN(baseTotal) || baseTotal === 0) {
alert("Please enter valid numbers for Indirect Expenses and Total Allocation Base. The base cannot be zero.");
return;
}
// Logic
var rate = indirect / baseTotal;
var rateText = "";
var formulaText = "";
var allocated = 0;
var totalJob = 0;
// Formatting Results based on Type
if (type === 'laborCost') {
// Result is a percentage
var percentage = rate * 100;
rateText = percentage.toFixed(2) + "% of Direct Labor Cost";
formulaText = "$" + indirect.toLocaleString() + " / $" + baseTotal.toLocaleString();
} else {
// Result is currency per unit
rateText = "$" + rate.toFixed(2) + " per Hour";
formulaText = "$" + indirect.toLocaleString() + " / " + baseTotal.toLocaleString() + " Hours";
}
// Calculate Project Allocation if input exists
var allocationText = "N/A";
var totalJobText = "N/A";
if (!isNaN(projectVal)) {
allocated = rate * projectVal;
allocationText = "$" + allocated.toFixed(2);
// If the base is Labor Cost, the total job impact is Labor Cost + Overhead
// If the base is Hours, we generally only calculate the overhead portion here,
// but for simplicity in "impact", we show the overhead cost.
// However, strictly speaking, Total Job Cost = Prime Cost + Overhead.
// Here we define "Impact" as the Base Cost (if monetary) + Overhead.
if (type === 'laborCost') {
totalJob = projectVal + allocated;
totalJobText = "$" + totalJob.toFixed(2);
} else {
// For hours, we cannot add hours + dollars. So we just show the allocated overhead dollar amount as the impact.
totalJobText = "$" + allocated.toFixed(2) + " (Overhead Portion Only)";
}
}
// Output
document.getElementById('displayRate').innerText = rateText;
document.getElementById('displayFormula').innerText = formulaText;
document.getElementById('displayAllocation').innerText = allocationText;
document.getElementById('displayTotalJob').innerText = totalJobText;
document.getElementById('result').style.display = 'block';
}
What is an Overhead Rate?
The Overhead Rate (often called the Predetermined Overhead Rate) is a calculation used in accounting to allocate indirect costs to specific products, jobs, or services. Unlike direct costs (like raw materials and direct labor), indirect costs cannot be traced directly to a single unit of production. These include expenses such as factory rent, electricity, equipment depreciation, and administrative salaries.
By calculating an overhead rate, businesses can accurately price their products and understand the true cost of production. Without applying overhead, a company might sell a product for more than the direct material and labor costs yet still lose money because they failed to account for the facility's operating expenses.
How to Calculate Overhead Rate
The formula for calculating the overhead rate is straightforward, but it requires accurate data aggregation from your financial records.
Overhead Rate Formula:
Overhead Rate = Total Estimated Indirect Costs / Total Estimated Allocation Base
The Allocation Base is the driver used to assign costs. Common bases include:
Direct Labor Cost ($): Useful when production is labor-intensive and wages vary significantly. The result is expressed as a percentage.
Direct Labor Hours: Useful when labor is the primary driver but wage rates are uniform. The result is expressed as $ per hour.
Machine Hours: Best for automated manufacturing where machinery drives costs more than human labor. The result is expressed as $ per machine hour.
How to Use the Overhead Rate
Once you have calculated the rate, you "apply" it to specific jobs to determine the full cost of that job. This is known as Applied Overhead.
Example:
Imagine your total factory overhead is $100,000 and your total direct labor cost is $50,000.