How to Calculate How Much Tile You Need

Ordering tile is one of the few parts of a renovation you can get exactly right before anyone picks up a trowel. Get the math wrong, though, and you either pay for a second shipment or end up with four boxes you can’t return. Here’s how to get it right.

Start with square footage

Measure the length and width of your space in feet, then multiply. A bathroom floor that measures 8 feet by 5 feet is 40 square feet. If the room isn’t a simple rectangle, break it into rectangles, calculate each one separately, and add the results together.

For walls and backsplashes, measure height and width the same way. A backsplash running 12 feet long with an 18-inch gap between counter and cabinets is 12 × 1.5 = 18 square feet.

Subtract large openings — but only large ones

Doorways, windows, and shower niches can be subtracted from your total. That said, only bother with openings larger than about 10 square feet. Smaller cutouts generate offcuts you’ll need anyway, and subtracting them tends to leave you short.

Add a waste factor

This is the step people skip. Every installation produces cuts, and some tiles arrive chipped or with variation you’d rather not use. Standard guidance:

• 10% for a straight grid layout on a square room
• 15% for diagonal, herringbone, or offset patterns
• 15–20% for rooms with lots of angles, or for large-format tile where a single bad cut wastes a lot of material

So that 40-square-foot bathroom floor in a straight layout becomes 44 square feet. In herringbone, closer to 46.

Round up to full boxes

Tile ships by the box, and boxes cover a fixed number of square feet. If a box covers 10.76 sq ft and you need 46 sq ft, that’s 4.27 boxes — order 5. Our product pages show coverage per box and calculate this for you when you enter your project size.

Order it all at once

Natural stone varies from batch to batch. Two orders of the same marble placed a month apart can differ noticeably in tone and veining. Ordering everything in a single shipment keeps your material consistent, and it’s cheaper than paying freight twice.

Keep the leftovers

Set aside a few spare tiles after the job is done. Cracks happen — a dropped pan, a settling subfloor — and having matching replacements on hand turns a costly repair into a 20-minute fix.

Quick summary

1. Measure length × width for each area
2. Add the areas together
3. Subtract openings over 10 sq ft
4. Add 10–20% for waste
5. Round up to full boxes
6. Order everything in one shipment

Not sure about your numbers? Order a sample first, and reach out with your measurements — we’re happy to check the math with you.