Online Wallpaper Calculator

Wallpaper Roll Calculator

Use this calculator to estimate the number of wallpaper rolls you'll need for your room. Accurate measurements are key to avoiding waste or running short.

Room Dimensions

Obstacles (Doors & Windows)

Enter the number and average dimensions of doors and windows to subtract their area from the total wall area.

Wallpaper Roll Details

function calculateWallpaper() { var roomLength = parseFloat(document.getElementById('roomLength').value); var roomWidth = parseFloat(document.getElementById('roomWidth').value); var roomHeight = parseFloat(document.getElementById('roomHeight').value); var numDoors = parseInt(document.getElementById('numDoors').value); var doorHeight = parseFloat(document.getElementById('doorHeight').value); var doorWidth = parseFloat(document.getElementById('doorWidth').value); var numWindows = parseInt(document.getElementById('numWindows').value); var windowHeight = parseFloat(document.getElementById('windowHeight').value); var windowWidth = parseFloat(document.getElementById('windowWidth').value); var rollLength = parseFloat(document.getElementById('rollLength').value); var rollWidth = parseFloat(document.getElementById('rollWidth').value); var patternRepeatCm = parseFloat(document.getElementById('patternRepeat').value); var extraPercentage = parseFloat(document.getElementById('extraPercentage').value); var resultDiv = document.getElementById('wallpaperResult'); resultDiv.innerHTML = "; // Clear previous results // Input validation if (isNaN(roomLength) || isNaN(roomWidth) || isNaN(roomHeight) || isNaN(numDoors) || isNaN(doorHeight) || isNaN(doorWidth) || isNaN(numWindows) || isNaN(windowHeight) || isNaN(windowWidth) || isNaN(rollLength) || isNaN(rollWidth) || isNaN(patternRepeatCm) || isNaN(extraPercentage) || roomLength <= 0 || roomWidth <= 0 || roomHeight <= 0 || rollLength <= 0 || rollWidth <= 0) { resultDiv.innerHTML = 'Please enter valid positive numbers for all required fields.'; return; } // Convert pattern repeat to meters var patternRepeatM = patternRepeatCm / 100; // 1. Calculate total wall perimeter var perimeter = 2 * (roomLength + roomWidth); // 2. Calculate total wall area var totalWallArea = perimeter * roomHeight; // 3. Calculate area of doors to subtract var doorArea = numDoors * doorHeight * doorWidth; if (doorArea < 0) doorArea = 0; // Ensure non-negative // 4. Calculate area of windows to subtract var windowArea = numWindows * windowHeight * windowWidth; if (windowArea < 0) windowArea = 0; // Ensure non-negative // 5. Calculate net wall area to cover var netWallArea = totalWallArea – doorArea – windowArea; if (netWallArea < 0) netWallArea = 0; // Cannot have negative area // 6. Calculate effective height per strip (room height + pattern repeat for matching) var effectiveStripHeight = roomHeight + patternRepeatM; // 7. Calculate how many full strips can be cut from one roll var stripsPerRoll = Math.floor(rollLength / effectiveStripHeight); if (stripsPerRoll <= 0) { resultDiv.innerHTML = 'Error: Wallpaper roll is too short for even one strip, considering pattern repeat. Please check dimensions.'; return; } // 8. Calculate total number of strips needed for the net wall area var totalStripsNeeded = Math.ceil(netWallArea / rollWidth); // 9. Calculate raw number of rolls needed var rawRollsNeeded = totalStripsNeeded / stripsPerRoll; // 10. Apply extra percentage for waste, cutting errors, future repairs var rollsWithExtra = rawRollsNeeded * (1 + extraPercentage / 100); // 11. Round up to the nearest whole roll var finalRolls = Math.ceil(rollsWithExtra); resultDiv.innerHTML = '

Calculation Results:

'; resultDiv.innerHTML += 'Total Wall Area: ' + totalWallArea.toFixed(2) + ' m²'; resultDiv.innerHTML += 'Area of Doors to Subtract: ' + doorArea.toFixed(2) + ' m²'; resultDiv.innerHTML += 'Area of Windows to Subtract: ' + windowArea.toFixed(2) + ' m²'; resultDiv.innerHTML += 'Net Wall Area to Cover: ' + netWallArea.toFixed(2) + ' m²'; resultDiv.innerHTML += 'Strips per Roll (approx): ' + stripsPerRoll + "; resultDiv.innerHTML += 'Total Strips Needed: ' + totalStripsNeeded + "; resultDiv.innerHTML += 'Estimated Rolls (before extra): ' + rawRollsNeeded.toFixed(2) + "; resultDiv.innerHTML += 'Recommended Wallpaper Rolls: ' + finalRolls + ''; } .wallpaper-calculator-container { font-family: Arial, sans-serif; max-width: 700px; margin: 20px auto; padding: 20px; border: 1px solid #ccc; border-radius: 8px; background-color: #f9f9f9; } .wallpaper-calculator-container h2, .wallpaper-calculator-container h3 { color: #333; text-align: center; margin-bottom: 15px; } .wallpaper-calculator-container label { display: inline-block; width: 250px; margin-bottom: 5px; font-weight: normal; } .wallpaper-calculator-container input[type="number"] { width: 150px; padding: 8px; margin-bottom: 10px; border: 1px solid #ddd; border-radius: 4px; } .wallpaper-calculator-container button { background-color: #007bff; color: white; padding: 10px 15px; border: none; border-radius: 4px; cursor: pointer; font-size: 16px; display: block; margin: 20px auto 10px auto; } .wallpaper-calculator-container button:hover { background-color: #0056b3; } .wallpaper-calculator-container #wallpaperResult { margin-top: 20px; padding: 15px; border: 1px solid #e0e0e0; border-radius: 4px; background-color: #eaf7ff; color: #333; } .wallpaper-calculator-container #wallpaperResult strong { color: #0056b3; font-size: 1.1em; }

Understanding Your Wallpaper Needs: A Comprehensive Guide

Wallpaper can dramatically transform a room, adding texture, color, and personality. However, accurately estimating how much wallpaper you need is crucial to a successful project. Buying too little means delays and potential color mismatches if you need to reorder, while buying too much leads to unnecessary waste and cost. Our Wallpaper Roll Calculator simplifies this process, helping you get the right amount every time.

How to Use the Wallpaper Roll Calculator

Our calculator takes into account all the critical dimensions of your room and your chosen wallpaper to provide a precise estimate. Here's a breakdown of each input:

• Room Length (meters): Measure the length of your room along one wall.
• Room Width (meters): Measure the width of your room along an adjacent wall.
• Room Height (meters): Measure the height from the floor to the ceiling. Take several measurements around the room, especially in older homes, and use the tallest measurement to ensure you have enough length for each strip.
• Number of Doors & Windows: Count how many doors and windows are in the room.
• Average Door/Window Height & Width (meters): Measure the average height and width of your doors and windows. The calculator will subtract these areas from the total wall area, as you won't be wallpapering over them.
• Wallpaper Roll Length (meters): This is typically found on the wallpaper packaging. Standard rolls are often 10.05 meters long.
• Wallpaper Roll Width (meters): Also found on the packaging. Common widths are 0.53 meters.
• Pattern Repeat (cm): If your wallpaper has a pattern, it will have a repeat measurement. This is the distance between where the pattern repeats itself. This is crucial for matching strips and will add to the effective height needed for each strip, increasing waste. If your wallpaper is plain or has a random match, enter '0'.
• Extra for Waste/Matching (%): It's always wise to add an extra percentage for cutting errors, pattern matching adjustments, and potential future repairs. A 10% to 15% buffer is generally recommended.

The Calculation Process Explained

The calculator follows a logical step-by-step process to determine your wallpaper needs:

1. Total Wall Area: It first calculates the total surface area of all walls in your room.
2. Subtracting Obstacles: The areas of your doors and windows are then subtracted from the total wall area, as these sections won't be wallpapered. This gives you the 'Net Wall Area'.
3. Effective Strip Height: For patterned wallpaper, the pattern repeat is added to the room height to determine the actual length of each strip you'll need to cut to ensure the pattern matches seamlessly.
4. Strips Per Roll: It then calculates how many full, usable strips can be cut from a single roll, considering the effective strip height.
5. Total Strips Needed: Based on the net wall area and the width of your wallpaper roll, the calculator determines the total number of strips required to cover all walls.
6. Raw Rolls Needed: This is simply the total strips needed divided by the strips you can get from one roll.
7. Adding Buffer & Final Rounding: Finally, the specified extra percentage is applied, and the result is rounded up to the nearest whole roll, ensuring you have enough wallpaper for your project.

Realistic Example

Let's say you have a room with the following dimensions:

• Room Length: 4.0 meters
• Room Width: 3.5 meters
• Room Height: 2.4 meters
• 1 Door (2.1m H x 0.8m W)
• 1 Window (1.2m H x 1.2m W)
• Wallpaper Roll Length: 10.05 meters
• Wallpaper Roll Width: 0.53 meters
• Pattern Repeat: 53 cm (0.53 meters)
• Extra Percentage: 10%

Using these inputs, the calculator would perform the following steps:

• Perimeter: 2 * (4.0 + 3.5) = 15.0 meters
• Total Wall Area: 15.0 * 2.4 = 36.0 m²
• Door Area: 1 * 2.1 * 0.8 = 1.68 m²
• Window Area: 1 * 1.2 * 1.2 = 1.44 m²
• Net Wall Area: 36.0 – 1.68 – 1.44 = 32.88 m²
• Effective Strip Height: 2.4 + 0.53 = 2.93 meters
• Strips Per Roll: Floor(10.05 / 2.93) = 3 strips
• Total Strips Needed: Ceil(32.88 / 0.53) = 63 strips
• Raw Rolls Needed: 63 / 3 = 21 rolls
• Rolls with Extra: 21 * (1 + 0.10) = 23.1 rolls
• Final Recommended Rolls: 24 rolls

Tips for Wallpapering Success

• Measure Twice, Cut Once: Always double-check your room measurements. Small errors can lead to big problems.
• Consider Pattern Match: If your wallpaper has a large or intricate pattern, you might need slightly more rolls than estimated due to the waste involved in matching.
• Buy from the Same Batch: When purchasing, ensure all rolls come from the same dye lot or batch number. This prevents subtle color variations between rolls.
• Prepare Your Walls: Ensure your walls are clean, smooth, and primed before applying wallpaper for the best adhesion and finish.
• Keep Leftovers: Save any leftover wallpaper for future repairs or touch-ups.

By using this calculator and following these tips, you'll be well on your way to a beautifully wallpapered room!