How to Calculate Variable Overhead Rate Variance

Variable Overhead Rate Variance Calculator

Calculation Result


What is Variable Overhead Rate Variance?

Variable overhead rate variance measures the difference between the actual variable manufacturing overhead cost incurred and the standard cost that should have been incurred for the actual hours worked. In simpler terms, it identifies whether you paid more or less per hour for variable overhead (like utilities or supplies) than you planned.

The Formula

Variable Overhead Rate Variance = (AR – SR) × AH
  • AR: Actual Rate (Actual Cost / Actual Hours)
  • SR: Standard Rate per hour
  • AH: Actual Hours Worked

Favorable vs. Unfavorable

  • Favorable Variance (F): Occurs when the actual variable overhead cost is lower than the standard cost for the hours worked. This suggests better-than-expected cost control.
  • Unfavorable Variance (U): Occurs when actual costs exceed the standard. This might be due to rising energy prices, inefficient use of indirect materials, or unexpected maintenance costs.

Example Calculation

Suppose your factory expected to pay $5.00 per hour for variable overhead (Standard Rate). Last month, your staff worked 1,200 hours and you spent a total of $6,500 on variable overhead costs.

  1. Actual Hours (AH): 1,200
  2. Standard Cost (AH × SR): 1,200 × $5.00 = $6,000
  3. Actual Cost: $6,500
  4. Variance: $6,500 – $6,000 = $500 Unfavorable

This means you spent $500 more than the budget allowed for those specific hours worked.

function calculateOverheadVariance() { var ah = parseFloat(document.getElementById('actualHours').value); var ac = parseFloat(document.getElementById('actualCost').value); var sr = parseFloat(document.getElementById('standardRate').value); var resultDiv = document.getElementById('varianceResult'); var amountP = document.getElementById('varianceAmount'); var descP = document.getElementById('varianceDescription'); if (isNaN(ah) || isNaN(ac) || isNaN(sr) || ah 0) { resultDiv.style.backgroundColor = '#fdecea'; amountP.style.color = '#c0392b'; amountP.innerHTML = '$' + variance.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + ' Unfavorable'; descP.innerHTML = "Your actual overhead rate was $" + actualRate.toFixed(2) + " per hour, which is $" + (actualRate – sr).toFixed(2) + " higher than your standard rate of $" + sr.toFixed(2) + "."; } else if (variance < 0) { resultDiv.style.backgroundColor = '#eafaf1'; amountP.style.color = '#27ae60'; amountP.innerHTML = '$' + Math.abs(variance).toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + ' Favorable'; descP.innerHTML = "Your actual overhead rate was $" + actualRate.toFixed(2) + " per hour, which is $" + (sr – actualRate).toFixed(2) + " lower than your standard rate of $" + sr.toFixed(2) + "."; } else { resultDiv.style.backgroundColor = '#f4f6f7'; amountP.style.color = '#2c3e50'; amountP.innerHTML = '$0.00 (No Variance)'; descP.innerHTML = "Your actual overhead rate perfectly matched your standard rate."; } }

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