Tile calculators are extremely useful tools for any home project involving tile installation. Knowing precisely how much tile is needed for a space prevents headaches caused by ordering too little or wasting money on excess materials. This guide will provide step-by-step instructions on using a tile calculator for home renovation or decor projects.

Selecting the Right Tile Calculator

There are many tile calculators available online, but not all are created equal. When choosing a calculator, consider the following features:

  • Room shape calculations – Some basic calculators only allow you to enter square footage, while more advanced ones can calculate tile needs for rectangular, L-shaped, and irregular rooms. Look for a calculator that can handle the shape of your space.
  • Incorporates tile dimensions – Make sure the calculator allows you to input the size of your actual tiles (12×24, 4×4, etc.). This ensures a more accurate estimate than just using square footage.
  • Calculates pattern layouts – The best tile calculators account for the pattern you want to lay the tiles in (herringbone, staggered, etc.) which affects tile quantities.
  • Handles multiple surfaces – For bathrooms especially, you may need to tile walls and floors. Opt for a calculator that can estimate tile for all the surfaces you plan to cover.
  • Allows waste factor input – Even experienced tilers end up with extra unusable tile pieces that go to waste. A good calculator will let you add a waste factor (often 10-15%).

The Home Depot Tile Calculator and the Lowe’s Tile Calculator incorporate all of these key features, so are great online tile calculator options.

Measuring the Installation Space

In order to use any tile calculator effectively, you need accurate room dimensions of the space you are tiling. Follow these steps:

For a regular square/rectangular room:

  • Measure the length and width of the room in feet to get the square footage. Include any alcoves or offsets.
  • For areas with multiple lengths/widths (like an L-shaped bath), measure each section separately.
  • Measure the height of each wall you plan to tile in feet.

For rooms with irregular shapes:

  • Break the area into smaller rectangles and squares. Measure the dimensions of each.
  • Sketch the layout of the entire space and label all measurements. This will be helpful when using the tile calculator.
  • Measure wall heights as above.

For outdoor installations:

  • Use stakes and string to outline the full area you want to tile.
  • Measure the length and width in feet, as if it were a regular rectangle.
  • For more complex outdoor shapes, divide into smaller sections as with irregular indoor rooms.

Accurate measurements are crucial! Even being a few inches off can significantly affect the tile needs estimate. Avoid guesstimating or rounding off numbers when measuring.

Entering Your Measurements into the Calculator

Once you have carefully measured the installation area(s), it’s time to input those dimensions into the tile calculator. Here is the step-by-step process:

  1. Select tile calculator app or website – As recommended above, choose a calculator with all the key features you’ll need. Home Depot and Lowe’s offer excellent calculators.
  2. Enter room dimensions – For each room section, input the length, width and height (for walls) in feet. Input every surface you plan to tile on.
  3. Choose tile size – Select the size of the tile you will be installing (12×24, 16×16, 4×4 etc.). Make sure tile dimensions match what you plan to purchase.
  4. Select tile pattern (if applicable) – If laying tile in a pattern, choose the appropriate option – staggered, herringbone, basketweave, etc.
  5. Input waste factor – Add a waste factor percentage if your calculator allows it, usually 10-15%. This accounts for unusable cut tiles.
  6. Calculate – After entering all details, run the calculator to estimate the tile quantities needed.
  7. Repeat for all areas – If tiling multiple spaces, repeat the process individually for each room or surface.
  8. Print results – Print or screenshot the calculator results to reference when purchasing materials.

Double check all inputs to ensure the tile estimate is based on accurate measurements and details. If tiling over multiple days, measure each day’s area beforehand.

Purchasing Tile and Materials

With tile quantities calculated for the project, it’s time to purchase what you need based on the calculator results. Use the following guidelines when buying tile:

  • Review calculator quantities and purchase at least 10-15% more tile than estimated. It’s better to have extras than come up short.
  • Buy all tile needed for the entire project at once if possible for consistent dye lots and availability.
  • Have 10-20% extra tile left over in case future repairs or additions are needed.
  • Don’t rely on partial boxes – buy full, unopened boxes. Tile quality and color can vary from box to box.
  • Purchase recommended tiling prep materials like backerboard, thinset, grout, etc. based on the room size.
  • Buy a few extra tools like tile cutters, rubber grout floats, and sponges to have handy during installation.
  • For large projects, rent or purchase a tile wet saw for accurate cuts.

Always check tile before purchasing to verify colors, quality, and that quantities match what you ordered. It’s no fun to get home and realize the tile is nothing like you expected!

Adjusting Tile Purchases Mid-Project

Inevitably some measurement or calculation will be off during large tiling jobs. When you find yourself running low on tiles part way through installation, here are some options:

  • Confirm original measurements – Re-measure the remaining areas and double check the calculations. If the original measurements were inaccurate, re-measuring can provide the actual tile needed.
  • Purchase more of the same tile – Try to buy more of the same dye lot from the original supplier. Request tiles from boxes near your original batch.
  • Find close replacement tile – If the original is unavailable, look for similar tiles from alternate suppliers. Ask for samples to compare color, quality, and size.
  • Switch pattern layout – Change the installation pattern to one requiring fewer full tiles like grid or staggered layouts. May cause aesthetic issues.
  • Reduce tiled area – Cut the tiled area down to what you have tiles for already. Finish with an alternate material like wood or carpet.
  • Salvage cuts – Carefully re-align cuts to get usable pieces rather than sacrificing them as waste. May compromise grout lines.

Never attempt to stretch existing tiles further than calculated! Covering an insufficient area with too few tiles results in problems with spacing, patterns and grout lines.

Using Leftover Tiles for Backsplashes, Accents, Repairs

Assuming you purchased surplus tile, you can put those extras to good use:

  • Add a backsplash – Use leftover wall tiles to create a coordinating backsplash. Measure carefully and match grout lines.
  • Make mosaic accents – Mix and match fragment pieces to build a mosaic design tile insert or medallion.
  • Frame trims or niches – Border trims, niches and alcoves with coordinating tiles.
  • Fill in damages – Replace any cracked, chipped or broken tiles in the original installation using your extra tiles.
  • Replace problematic tiles – If any tiles crack or appear flawed after installation, swap in extras as replacements.
  • Add coordinated decor – Frame a mirror, shelving or artwork with scrap tile pieces to pull the design throughout the space.
  • Save for future repairs – Store extra tiles in case repairs or replacements are needed down the road.

With some creativity, even tile remnants and bits can be incorporated to build a cohesive look.

Frequently Asked Questions About Using Tile Calculators

Tile projects often spark lots of questions when it comes to effectively using calculators. Here are answers to some commonly asked questions:

How do I calculate tile layout patterns?

Quality tile calculators will account for the layout pattern automatically when you select it. Input the measurements, tile size, and then choose your desired pattern – staggered, herringbone, brick, etc. The calculator will adjust the tile estimate higher or lower as needed based on the layout.

What measurements do I need for outdoor tile projects?

Outdoor tile projects can have very irregular dimensions. Outline the full area with stakes and string, then measure the space as if it were a rectangle. Input the rectangular length x width measurements into the calculator. Divide oddly shaped sections into smaller rectangles and calculate each individually.

How do I calculate tile quantities for mosaic sheets?

Mosaic tile sheets come in standard sizes (often 12×12″) with multiple small tiles held together in a grid. To calculate needs, treat each sheet as one larger tile rather than trying to input each tiny mosaic piece size. Just be sure to multiply the number of sheets needed by the number of small tiles on each sheet.

How do I calculate a herringbone pattern with wood planks?

Wood planks don’t have the small uniform sizes that most tile calculators are designed for. For a herringbone wood pattern, make a sketch and calculate the staggered rows needed based on your plank length. Use your measurements and sketch to determine how many full and partial planks are needed overall.

What tile adjustments are needed for floor heating?

Floor heating systems require some tile modifications. Use smaller grout lines (1/8″ or less), choose tile with low water absorption, and use reactive resin adhesives instead of cement mortar when installing over radiant heat. Be sure your tile calculator accounts for these smaller grout lines in its estimate.


With some careful measurements, a quality tile calculator, and the guidelines provided above, you can determine tile needs for any tiling project in your home. Accurately estimating tile quantities takes the guesswork and stress out of purchasing. Just be sure to have some extras on hand for repairs and additions down the road. What tile project will you be tackling in your home next?