FIFO vs LIFO vs Weighted Average Cost: Inventory Valuation Calculator
Easily compare inventory valuation methods and understand their impact on your Cost of Goods Sold (COGS) and ending inventory values. Make informed decisions with our interactive tool and detailed guide on FIFO, LIFO, and Weighted Average cost calculations.
Inventory Cost Calculator
Purchases
Valuation Results
Calculation Basis:
Inventory valuation methods determine the cost of goods sold (COGS) and the value of ending inventory.
- FIFO (First-In, First-Out): Assumes the oldest inventory items are sold first.
- LIFO (Last-In, First-Out): Assumes the newest inventory items are sold first (not permitted under IFRS).
- Weighted Average Cost: Calculates an average cost for all inventory units available for sale.
| Period | Units | Cost Per Unit | Total Cost |
|---|
What is Inventory Valuation?
Inventory valuation refers to the accounting methods used to assign a cost to the inventory items a business holds and sells. It's a critical process for accurate financial reporting, impacting key metrics like Cost of Goods Sold (COGS) and the value of remaining inventory on the balance sheet. The chosen method directly affects a company's reported profit, tax liability, and overall financial health. Understanding these methods is essential for inventory management, financial analysis, and strategic business planning.
Different inventory valuation methods are used by businesses to account for the costs associated with their inventory. The primary goal is to accurately reflect the flow of costs through the business. The most common methods are:
- FIFO (First-In, First-Out): This method assumes that the first inventory items purchased are the first ones sold. Consequently, the cost of the oldest inventory is expensed as COGS, and the cost of the most recently purchased items remains in ending inventory.
- LIFO (Last-In, First-Out): This method assumes that the last inventory items purchased are the first ones sold. The cost of the most recent inventory is expensed as COGS, leaving the cost of the oldest inventory in ending inventory. It's important to note that LIFO is not permitted under International Financial Reporting Standards (IFRS) but is allowed under U.S. Generally Accepted Accounting Principles (GAAP).
- Weighted Average Cost: This method calculates a single average cost for all inventory available for sale during a period. It smooths out price fluctuations, providing a more stable cost figure. The weighted average cost is calculated by dividing the total cost of goods available for sale by the total number of units available for sale.
Who should use these methods? Any business that holds inventory and needs to track its costs. This includes retailers, manufacturers, wholesalers, and even some service-based businesses that deal with physical goods. The choice of method can significantly influence financial statements, especially during periods of changing prices.
Common Misconceptions: A frequent misunderstanding is that these methods dictate the *physical flow* of inventory. In reality, they are accounting conventions that assign costs. A company using FIFO, for example, might physically sell its newest items first, but the accounting method still assigns the cost of the oldest items to COGS. Another misconception is that LIFO is universally accepted; while permitted in some jurisdictions, its exclusion under IFRS makes it less globally relevant.
FIFO, LIFO, and Weighted Average Cost Formula and Mathematical Explanation
Understanding the underlying formulas is key to mastering inventory valuation. While our calculator simplifies the process, grasping the mechanics provides deeper insight.
FIFO (First-In, First-Out)
FIFO assumes the oldest inventory is sold first. To calculate COGS and ending inventory under FIFO:
- Cost of Goods Sold (COGS): Sum the costs of the earliest purchased inventory units until the total number of units sold is reached.
- Ending Inventory: The remaining units are valued at the cost of the most recently purchased inventory.
Formula:
COGS (FIFO) = Sum of costs of units from earliest purchases up to the quantity sold
Ending Inventory (FIFO) = Sum of costs of units from latest purchases up to the remaining quantity
LIFO (Last-In, First-Out)
LIFO assumes the newest inventory is sold first. To calculate COGS and ending inventory under LIFO:
- Cost of Goods Sold (COGS): Sum the costs of the most recently purchased inventory units until the total number of units sold is reached.
- Ending Inventory: The remaining units are valued at the cost of the oldest purchased inventory.
Formula:
COGS (LIFO) = Sum of costs of units from latest purchases up to the quantity sold
Ending Inventory (LIFO) = Sum of costs of units from earliest purchases up to the remaining quantity
Weighted Average Cost
The Weighted Average Cost method provides a blended cost per unit.
Formula:
1. Calculate Total Cost of Goods Available for Sale:
Total Cost Available = (Initial Quantity * Initial Cost) + Sum of (Purchase Quantity * Purchase Cost) for all purchases.
2. Calculate Total Units Available for Sale:
Total Units Available = Initial Quantity + Sum of Purchase Quantities for all purchases.
3. Calculate Weighted Average Cost Per Unit:
Weighted Average Cost Per Unit = Total Cost Available / Total Units Available
4. Calculate Cost of Goods Sold (COGS):
COGS (Weighted Average) = Units Sold * Weighted Average Cost Per Unit
5. Calculate Ending Inventory:
Ending Inventory (Weighted Average) = (Total Units Available – Units Sold) * Weighted Average Cost Per Unit
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Initial Quantity | Number of units at the beginning of the period. | Units | ≥ 0 |
| Initial Cost Per Unit | Cost to acquire one unit of the beginning inventory. | Currency (e.g., USD) | ≥ 0 |
| Purchase Quantity | Number of units acquired in a specific purchase transaction. | Units | ≥ 0 |
| Purchase Cost Per Unit | Cost to acquire one unit in a specific purchase transaction. | Currency (e.g., USD) | ≥ 0 |
| Units Sold | Number of inventory units sold during the period. | Units | ≥ 0, ≤ Total Units Available |
| COGS | Cost of Goods Sold – the direct costs attributable to the production or purchase of goods sold by a company. | Currency (e.g., USD) | ≥ 0 |
| Ending Inventory Value | Value of inventory remaining at the end of the accounting period. | Currency (e.g., USD) | ≥ 0 |
| Weighted Average Cost Per Unit | The average cost of all inventory units available for sale. | Currency (e.g., USD) | ≥ 0 |
Practical Examples (Real-World Use Cases)
Let's illustrate these methods with a practical example. Suppose a small electronics store, "Gadget Hub," is tracking its sales of a popular model of wireless earbuds.
Example 1: Gadget Hub – Wireless Earbuds
Scenario: Gadget Hub starts the month with 100 units of earbuds at a cost of $50 each. During the month, they make two purchases and sell a total of 250 units.
Inputs:
- Beginning Inventory: 100 units @ $50/unit
- Purchase 1: 150 units @ $55/unit
- Purchase 2: 100 units @ $60/unit
- Units Sold: 250 units
Calculations & Results (using the calculator above will provide these):
Total Units Available: 100 (initial) + 150 (P1) + 100 (P2) = 350 units
Total Cost Available: (100 * $50) + (150 * $55) + (100 * $60) = $5,000 + $8,250 + $6,000 = $19,250
FIFO Method:
- COGS: The first 250 units sold are assumed to be from the oldest stock.
- 100 units @ $50 = $5,000
- 150 units @ $55 = $8,250
- COGS = $5,000 + $8,250 = $13,250
- Ending Inventory: The remaining 100 units (350 total available – 250 sold) are valued at the latest costs.
- 100 units @ $60 = $6,000
- Check: COGS ($13,250) + Ending Inventory ($6,000) = $19,250 (Total Cost Available)
LIFO Method:
- COGS: The last 250 units purchased are assumed sold first.
- 100 units @ $60 = $6,000
- 150 units @ $55 = $8,250
- COGS = $6,000 + $8,250 = $14,250
- Ending Inventory: The remaining 100 units are valued at the oldest costs.
- 100 units @ $50 = $5,000
- Check: COGS ($14,250) + Ending Inventory ($5,000) = $19,250 (Total Cost Available)
Weighted Average Cost Method:
- Weighted Average Cost Per Unit: $19,250 / 350 units = $55/unit
- COGS: 250 units sold * $55/unit = $13,750
- Ending Inventory: (350 – 250) units * $55/unit = 100 units * $55/unit = $5,500
- Check: COGS ($13,750) + Ending Inventory ($5,500) = $19,250 (Total Cost Available)
Financial Interpretation: In this example with rising prices, LIFO results in the highest COGS ($14,250) and lowest ending inventory ($5,000), leading to lower reported profit and taxes. FIFO results in the lowest COGS ($13,250) and highest ending inventory ($6,000), leading to higher reported profit and taxes. The Weighted Average method provides a middle ground ($13,750 COGS, $5,500 ending inventory).
Example 2: Manufacturing Co. – Raw Material Widgets
Scenario: A manufacturer uses "Widgets" as a raw material. They need to value their inventory at the end of the quarter.
Inputs:
- Beginning Inventory: 500 units @ $10/unit
- Purchase 1: 1000 units @ $11/unit
- Purchase 2: 750 units @ $12/unit
- Units Sold (used in production): 1800 units
Calculations & Results:
Total Units Available: 500 + 1000 + 750 = 2250 units
Total Cost Available: (500 * $10) + (1000 * $11) + (750 * $12) = $5,000 + $11,000 + $9,000 = $25,000
FIFO Method:
- COGS: 500 @ $10 ($5,000) + 1000 @ $11 ($11,000) + 300 @ $12 ($3,600) = $19,600
- Ending Inventory: 450 @ $12 ($5,400)
- Check: $19,600 + $5,400 = $25,000
LIFO Method:
- COGS: 750 @ $12 ($9,000) + 1000 @ $11 ($11,000) + 50 @ $10 ($500) = $20,500
- Ending Inventory: 450 @ $10 ($4,500)
- Check: $20,500 + $4,500 = $25,000
Weighted Average Cost Method:
- Weighted Average Cost Per Unit: $25,000 / 2250 units = $11.11 (approx.)
- COGS: 1800 units * $11.11 = $19,998 (approx.)
- Ending Inventory: (2250 – 1800) units * $11.11 = 450 units * $11.11 = $4,999.50 (approx.)
- Check: $19,998 + $4,999.50 = $24,997.50 (slight difference due to rounding)
Financial Interpretation: In this scenario with rising prices, LIFO again yields higher COGS ($20,500) and lower ending inventory ($4,500) compared to FIFO ($19,600 COGS, $5,400 ending inventory). The Weighted Average method sits in between. The choice impacts reported profit and potentially tax obligations.
How to Use This Inventory Valuation Calculator
Our calculator simplifies the complex process of inventory valuation. Follow these steps to get accurate results:
- Enter Beginning Inventory: Input the quantity of inventory you had at the start of the period and its cost per unit.
- Add Purchases: For each purchase made during the period, click "Add Another Purchase" and enter the quantity and cost per unit for that specific transaction. You can add multiple purchases.
- Enter Units Sold: Input the total number of inventory units that were sold or used during the period.
- Calculate Costs: Click the "Calculate Costs" button. The calculator will instantly compute the COGS and ending inventory values for FIFO, LIFO, and Weighted Average methods.
- Review Results: The primary result shows the weighted average cost per unit. Intermediate results clearly display COGS and ending inventory for each method. The table provides a detailed breakdown of transactions, and the chart visually compares the ending inventory values.
- Understand the Formulas: Refer to the "Calculation Basis" section below the results for a plain-language explanation of how each method works.
- Use the Data: Analyze the differences between the methods. Higher COGS (like often seen with LIFO in rising price environments) leads to lower reported profit and taxes. Lower COGS (FIFO) leads to higher reported profit and taxes. The Weighted Average offers a blend.
- Reset or Copy: Use the "Reset" button to clear the fields and start over. Use the "Copy Results" button to copy all calculated values and key assumptions for use in reports or further analysis.
Decision-Making Guidance: The choice of inventory valuation method is an accounting policy decision. Consider the impact on your financial statements, tax implications, and industry practices. For tax purposes in the US, if LIFO is chosen for tax filings, it generally must also be used for financial reporting (the LIFO conformity rule). Consult with a qualified accountant to determine the best method for your specific business situation.
Key Factors That Affect Inventory Valuation Results
Several factors significantly influence the outcomes of FIFO, LIFO, and Weighted Average cost calculations. Understanding these is crucial for accurate interpretation:
- Inflation/Deflation (Price Trends): This is the most impactful factor. In periods of rising prices (inflation), LIFO generally results in higher COGS and lower ending inventory (and thus lower profit/taxes), while FIFO results in lower COGS and higher ending inventory (higher profit/taxes). The opposite occurs during deflation.
- Volatility of Purchase Costs: Significant price fluctuations between purchases make the Weighted Average Cost method more appealing for smoothing out results. High volatility can lead to substantial differences between FIFO and LIFO.
- Inventory Turnover Rate: Businesses with a high inventory turnover (selling goods quickly) might see less dramatic differences between methods compared to those with slow turnover, especially if purchase costs are relatively stable.
- Accounting Standards (IFRS vs. GAAP): The choice is constrained by regulations. IFRS prohibits LIFO, meaning companies reporting under IFRS must use FIFO or Weighted Average. U.S. GAAP permits LIFO, offering more flexibility but also complexity. Understanding accounting standards is vital.
- Tax Regulations: Tax laws can influence the choice. For example, in the U.S., the LIFO conformity rule links tax reporting with financial reporting if LIFO is chosen for tax purposes. Businesses might select a method that offers tax advantages, provided it complies with accounting standards.
- Management Decisions & Business Strategy: Management may choose a method based on desired financial reporting outcomes. For instance, reporting higher profits (via FIFO during inflation) might appeal to investors or lenders, while minimizing taxes (via LIFO during inflation) benefits cash flow.
- Type of Inventory: Perishable goods or items with short life cycles are often best suited to FIFO, as it better reflects the physical flow and reduces obsolescence risk.
- System Capabilities: Accurately implementing LIFO, especially with frequent purchases and sales, requires robust inventory management systems. Weighted Average can also require careful tracking. FIFO is often the simplest to manage operationally.
Frequently Asked Questions (FAQ)
Q1: Which inventory valuation method is best?
There is no single "best" method; it depends on your business, industry, accounting standards (IFRS vs. GAAP), tax regulations, and financial reporting goals. FIFO generally reflects physical flow for many businesses and often results in higher reported profits during inflation. LIFO (where permitted) can lower taxable income during inflation but is more complex. Weighted Average provides a smoothed cost. Consult a financial advisor.
Q2: Can I switch inventory valuation methods?
Switching methods is permitted but requires justification (e.g., the new method provides more reliable or relevant information) and must be disclosed in financial statements. Changes in accounting methods are complex and often require regulatory approval or auditor consultation.
Q3: Why is LIFO not allowed under IFRS?
IFRS aims for methods that best reflect the economic reality and comparability of financial statements globally. LIFO's potential to significantly differ from the physical flow of goods and its complexity in management are cited as reasons for its exclusion, promoting greater international consistency with FIFO and Weighted Average.
Q4: What happens if purchase prices decrease (deflation)?
During deflation (falling prices), the effects are reversed compared to inflation. FIFO will result in higher COGS and lower ending inventory (lower profit/taxes), while LIFO will result in lower COGS and higher ending inventory (higher profit/taxes). Weighted Average will reflect the declining average cost.
Q5: How does the calculator handle multiple purchases?
The calculator allows you to add multiple purchase entries. For FIFO and LIFO, it correctly matches the oldest or newest costs respectively against the units sold. For Weighted Average, it recalculates the average cost after incorporating all purchases before determining COGS and ending inventory.
Q6: What is the LIFO conformity rule?
The LIFO conformity rule, primarily in the U.S. under GAAP, states that if a company uses the LIFO method for tax reporting purposes, it must also use LIFO for its financial statements presented to owners and for credit purposes. This prevents companies from using LIFO to reduce taxes while reporting higher profits based on another method.
Q7: Does inventory valuation affect cash flow?
Yes, indirectly. By affecting reported profit, inventory valuation methods influence income tax payments. Choosing a method that results in higher COGS during inflationary periods (like LIFO) can lead to lower tax payments, thus improving short-term cash flow.
Q8: How does ending inventory value affect financial ratios?
The ending inventory value directly impacts the current assets on the balance sheet. This affects ratios like the current ratio (Current Assets / Current Liabilities) and quick ratio. It also influences the Cost of Goods Sold, which affects profitability ratios like Gross Profit Margin (Gross Profit / Revenue) and Inventory Turnover (COGS / Average Inventory). A higher ending inventory (often with FIFO in inflation) generally improves the current ratio but lowers inventory turnover.
Weighted Average Cost Per Unit
$${weightedAverageCostPerUnit.toFixed(2)}
`;
document.getElementById('cogsFifo').innerHTML = `FIFO COGS: $${cogsFifo.toFixed(2)}`;
document.getElementById('endingInventoryFifo').innerHTML = `FIFO Ending Inventory: $${(totalCostAvailable – cogsFifo).toFixed(2)}`; // Recalculate ending inv based on COGS for consistency
document.getElementById('cogsLifo').innerHTML = `LIFO COGS: $${cogsLifo.toFixed(2)}`;
document.getElementById('endingInventoryLifo').innerHTML = `LIFO Ending Inventory: $${(totalCostAvailable – cogsLifo).toFixed(2)}`; // Recalculate ending inv based on COGS for consistency
document.getElementById('weightedAverageCost').innerHTML = `Weighted Average Cost Per Unit: $${weightedAverageCostPerUnit.toFixed(2)}`;
document.getElementById('cogsWeightedAverage').innerHTML = `Weighted Average COGS: $${cogsWeightedAverage.toFixed(2)}`;
document.getElementById('endingInventoryWeightedAverage').innerHTML = `Weighted Average Ending Inventory: $${endingInventoryValueWeightedAverage.toFixed(2)}`;
// — Populate Table —
var tableBody = document.getElementById('inventoryTableBody');
transactionData.forEach(function(transaction, index) {
if (transaction.period === 'Units Sold') {
// Special handling for Units Sold row, costs will be assigned by method later
var row = tableBody.insertRow();
row.insertCell(0).textContent = transaction.period;
row.insertCell(1).textContent = transaction.quantity;
row.insertCell(2).textContent = "-"; // Cost per unit not applicable here directly
row.insertCell(3).textContent = "-"; // Total cost not applicable here directly
} else {
var row = tableBody.insertRow();
row.insertCell(0).textContent = transaction.period;
row.insertCell(1).textContent = transaction.quantity;
row.insertCell(2).textContent = '$' + transaction.costPerUnit.toFixed(2);
row.insertCell(3).textContent = '$' + transaction.totalCost.toFixed(2);
}
});
// Add calculated COGS and Ending Inventory to the table conceptually
var rowCOGS = tableBody.insertRow();
rowCOGS.style.fontWeight = 'bold';
rowCOGS.style.backgroundColor = '#fff3cd'; // Light yellow for emphasis
rowCOGS.insertCell(0).textContent = "FIFO COGS";
rowCOGS.insertCell(1).textContent = "";
rowCOGS.insertCell(2).textContent = "";
rowCOGS.insertCell(3).textContent = '$' + cogsFifo.toFixed(2);
var rowEndingFIFO = tableBody.insertRow();
rowEndingFIFO.style.fontWeight = 'bold';
rowEndingFIFO.style.backgroundColor = '#d4edda'; // Light green for emphasis
rowEndingFIFO.insertCell(0).textContent = "FIFO Ending Inventory";
rowEndingFIFO.insertCell(1).textContent = "";
rowEndingFIFO.insertCell(2).textContent = "";
rowEndingFIFO.insertCell(3).textContent = '$' + (totalCostAvailable – cogsFifo).toFixed(2);
var rowLIFO_COGS = tableBody.insertRow();
rowLIFO_COGS.style.fontWeight = 'bold';
rowLIFO_COGS.style.backgroundColor = '#f8d7da'; // Light red for emphasis
rowLIFO_COGS.insertCell(0).textContent = "LIFO COGS";
rowLIFO_COGS.insertCell(1).textContent = "";
rowLIFO_COGS.insertCell(2).textContent = "";
rowLIFO_COGS.insertCell(3).textContent = '$' + cogsLifo.toFixed(2);
var rowEndingLIFO = tableBody.insertRow();
rowEndingLIFO.style.fontWeight = 'bold';
rowEndingLIFO.style.backgroundColor = '#f8d7da'; // Light red for emphasis
rowEndingLIFO.insertCell(0).textContent = "LIFO Ending Inventory";
rowEndingLIFO.insertCell(1).textContent = "";
rowEndingLIFO.insertCell(2).textContent = "";
rowEndingLIFO.insertCell(3).textContent = '$' + (totalCostAvailable – cogsLifo).toFixed(2);
var rowWAvg_COGS = tableBody.insertRow();
rowWAvg_COGS.style.fontWeight = 'bold';
rowWAvg_COGS.style.backgroundColor = '#cce5ff'; // Light blue for emphasis
rowWAvg_COGS.insertCell(0).textContent = "Weighted Avg COGS";
rowWAvg_COGS.insertCell(1).textContent = "";
rowWAvg_COGS.insertCell(2).textContent = "";
rowWAvg_COGS.insertCell(3).textContent = '$' + cogsWeightedAverage.toFixed(2);
var rowEndingWAvg = tableBody.insertRow();
rowEndingWAvg.style.fontWeight = 'bold';
rowEndingWAvg.style.backgroundColor = '#cce5ff'; // Light blue for emphasis
rowEndingWAvg.insertCell(0).textContent = "Weighted Avg Ending Inventory";
rowEndingWAvg.insertCell(1).textContent = "";
rowEndingWAvg.insertCell(2).textContent = "";
rowEndingWAvg.insertCell(3).textContent = '$' + endingInventoryValueWeightedAverage.toFixed(2);
// Add totals row
var totalRow = tableBody.insertRow();
totalRow.style.fontWeight = 'bold';
totalRow.style.backgroundColor = '#e9ecef'; // Light gray
totalRow.insertCell(0).textContent = "Total Available for Sale";
totalRow.insertCell(1).textContent = totalUnitsAvailable;
totalRow.insertCell(2).textContent = "";
totalRow.insertCell(3).textContent = '$' + totalCostAvailable.toFixed(2);
// — Populate Chart —
updateChart(cogsFifo, cogsLifo, cogsWeightedAverage,
(totalCostAvailable – cogsFifo), (totalCostAvailable – cogsLifo), endingInventoryValueWeightedAverage);
}
function updateChart(cogsFifo, cogsLifo, cogsWeightedAverage, endInvFifo, endInvLifo, endInvWeightedAverage) {
var ctx = document.getElementById('inventoryChart').getContext('2d');
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
// Define chart data based on whether LIFO is relevant (Not allowed by IFRS, but calculated for US GAAP context)
var labels = ['FIFO', 'LIFO', 'Weighted Average'];
var cogsData = [cogsFifo, cogsLifo, cogsWeightedAverage];
var endingInventoryData = [endInvFifo, endInvLifo, endInvWeightedAverage];
// Ensure LIFO data is presented correctly if needed, otherwise filter or adapt
// For this example, we'll show LIFO as calculated, assuming a GAAP context for comparison.
var chartData = {
labels: labels,
datasets: [
{
label: 'Cost of Goods Sold (COGS)',
data: cogsData,
backgroundColor: 'rgba(0, 74, 153, 0.6)', // Primary color, semi-transparent
borderColor: 'rgba(0, 74, 153, 1)',
borderWidth: 1
},
{
label: 'Ending Inventory Value',
data: endingInventoryData,
backgroundColor: 'rgba(40, 167, 69, 0.6)', // Success color, semi-transparent
borderColor: 'rgba(40, 167, 69, 1)',
borderWidth: 1
}
]
};
var chartOptions = {
responsive: true,
maintainAspectRatio: true, // Allow canvas to scale responsively
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Value ($)'
}
},
x: {
title: {
display: true,
text: 'Valuation Method'
}
}
},
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Comparison of COGS and Ending Inventory by Method'
}
}
};
chartInstance = new Chart(ctx, {
type: 'bar',
data: chartData,
options: chartOptions
});
// Update legend text
var legendHtml = `
COGS
Ending Inventory
`;
document.getElementById('chartLegend').innerHTML = legendHtml;
}
function resetCalculator() {
document.getElementById('initialQuantity').value = '100';
document.getElementById('initialCostPerUnit').value = '5.00';
document.getElementById('salesQuantity').value = '120';
// Remove dynamically added purchase entries
var purchaseEntries = document.querySelectorAll('.purchase-entry');
for (var i = 1; i < purchaseEntries.length; i++) { // Start from index 1 to keep the first one
purchaseEntries[i].remove();
}
purchaseCounter = 1; // Reset counter
// Clear errors
var errorMessages = document.querySelectorAll('.error-message');
errorMessages.forEach(function(el) { el.textContent = ''; });
var inputFields = document.querySelectorAll('input');
inputFields.forEach(function(el) { el.classList.remove('error-border'); });
// Clear results
document.getElementById('primary-result').innerHTML = '';
document.getElementById('cogsFifo').innerHTML = '';
document.getElementById('endingInventoryFifo').innerHTML = '';
document.getElementById('cogsLifo').innerHTML = '';
document.getElementById('endingInventoryLifo').innerHTML = '';
document.getElementById('weightedAverageCost').innerHTML = '';
document.getElementById('cogsWeightedAverage').innerHTML = '';
document.getElementById('endingInventoryWeightedAverage').innerHTML = '';
document.getElementById('inventoryTableBody').innerHTML = '';
// Clear chart
var canvas = document.getElementById('inventoryChart');
var context = canvas.getContext('2d');
context.clearRect(0, 0, canvas.width, canvas.height);
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
document.getElementById('chartLegend').innerHTML = '';
// Optional: Re-run calculation with default values if desired, or just reset visually
// calculateInventoryCosts();
}
function copyResults() {
var resultsText = "Inventory Valuation Results:\n\n";
resultsText += "Key Assumptions:\n";
resultsText += "- Beginning Inventory Quantity: " + document.getElementById('initialQuantity').value + "\n";
resultsText += "- Beginning Inventory Cost/Unit: $" + parseFloat(document.getElementById('initialCostPerUnit').value).toFixed(2) + "\n";
var purchaseQuantityInputs = document.querySelectorAll('.purchaseQuantity');
var purchaseCostInputs = document.querySelectorAll('.purchaseCostPerUnit');
for (var i = 0; i < purchaseQuantityInputs.length; i++) {
resultsText += `- Purchase ${i + 1} Quantity: ${purchaseQuantityInputs[i].value}\n`;
resultsText += `- Purchase ${i + 1} Cost/Unit: $${parseFloat(purchaseCostInputs[i].value).toFixed(2)}\n`;
}
resultsText += "- Units Sold: " + document.getElementById('salesQuantity').value + "\n\n";
resultsText += "FIFO:\n";
resultsText += "- COGS: " + document.getElementById('cogsFifo').textContent + "\n";
resultsText += "- Ending Inventory: " + document.getElementById('endingInventoryFifo').textContent + "\n\n";
resultsText += "LIFO:\n";
resultsText += "- COGS: " + document.getElementById('cogsLifo').textContent + "\n";
resultsText += "- Ending Inventory: " + document.getElementById('endingInventoryLifo').textContent + "\n\n";
resultsText += "Weighted Average:\n";
resultsText += "- Cost Per Unit: " + document.getElementById('weightedAverageCost').textContent + "\n";
resultsText += "- COGS: " + document.getElementById('cogsWeightedAverage').textContent + "\n";
resultsText += "- Ending Inventory: " + document.getElementById('endingInventoryWeightedAverage').textContent + "\n";
// Use a temporary textarea to copy
var textArea = document.createElement("textarea");
textArea.value = resultsText;
document.body.appendChild(textArea);
textArea.select();
try {
document.execCommand("copy");
alert("Results copied to clipboard!");
} catch (e) {
console.error("Failed to copy results:", e);
alert("Copying failed. Please copy manually.");
}
document.body.removeChild(textArea);
}
function toggleFaq(element) {
var answer = element.nextElementSibling;
answer.classList.toggle('show');
}
// Initial calculation on load if default values are present
document.addEventListener('DOMContentLoaded', function() {
// Set default values if inputs are empty
if (document.getElementById('initialQuantity').value === "") document.getElementById('initialQuantity').value = '100';
if (document.getElementById('initialCostPerUnit').value === "") document.getElementById('initialCostPerUnit').value = '5.00';
if (document.getElementById('salesQuantity').value === "") document.getElementById('salesQuantity').value = '120';
// Ensure at least one purchase input is visible by default
var purchaseQtyInputs = document.querySelectorAll('.purchaseQuantity');
if(purchaseQtyInputs.length === 0 || purchaseQtyInputs[0].value === ""){
if (document.querySelectorAll('.purchaseQuantity')[0]) document.querySelectorAll('.purchaseQuantity')[0].value = '50';
if (document.querySelectorAll('.purchaseCostPerUnit')[0]) document.querySelectorAll('.purchaseCostPerUnit')[0].value = '5.50';
}
calculateInventoryCosts(); // Perform initial calculation
});
// Add event listeners for real-time updates (optional, but good UX)
var inputFields = document.querySelectorAll('#inventory-calculator input');
inputFields.forEach(function(input) {
input.addEventListener('input', calculateInventoryCosts);
});
// Also listen for dynamic purchase inputs
document.getElementById('purchasesContainer').addEventListener('input', function(e) {
if (e.target.classList.contains('purchaseQuantity') || e.target.classList.contains('purchaseCostPerUnit')) {
calculateInventoryCosts();
}
});
// Chart.js library – needs to be included via CDN or locally if not already present in your WP theme/setup.
// For a single HTML file, it's common to include it directly in the head via CDN.
// ADD THIS TO YOUR SECTION IF NOT ALREADY PRESENT:
//
// Since this is a self-contained HTML output, I will assume Chart.js is available.
// If running this in a WordPress theme, ensure Chart.js is enqueued properly.