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How to Measure for Tile

Accurate tile quantity starts with measurements you can actually enter: rectangles, consistent units, and openings that will not receive tile. A measurement error carries through to the area you enter and can affect every calculation that follows.

Open the Tile Calculator

Quick Answer

Measure each tiled surface as a rectangle (length × width for floors; width × height for walls, showers, and backsplashes). If the space is L-shaped or irregular, split it into rectangles and add those areas. Deduct doors, windows, and other openings only when they will not be tiled. Then enter those numbers in the Tile Calculator so it can calculate quantity, waste, boxes, and estimated tile material cost.

Keep Units Consistent

Pick Imperial (feet and inches) or Metric (meters, centimeters, millimeters) and stay with it. Mixing a room measured in feet with a tile size in centimeters without converting is a common source of bad estimates. The calculator has an Imperial/Metric switch so the labels match your tape.

How to Measure a Floor

For a rectangular floor, measure length and width. Area is length × width. A 10 ft × 12 ft room is 120 sq ft. Measure along the walls that will receive tile, not along furniture or a shortcut across the room.

If you have more than one room on the same tile, measure each room and enter it as a separate area so the calculator combines them before waste.

How to Measure a Wall

Wall tile uses wall width × wall height. Measure the width of the wall and the height you actually plan to tile (full height, wainscot, or a band). If a door or window will not receive tile, record it as an opening instead of pretending the wall is smaller than it is.

How to Measure a Shower

Showers are usually several rectangles, not one floor plane. Measure each shower wall, and the floor if it is tiled. Add those areas. Deduct a niche or door opening only if that surface will not be tiled. Corners, benches, and niches add cutting later — that is a waste decision, not a reason to skip measuring a face.

How to Measure a Backsplash

Measure the backsplash field as width × height. If a window or large appliance cutout will not be tiled, deduct that opening. Small outlet holes are usually not worth deducting as area; they still use tile and often increase cuts.

Openings and Deductions

If a door, window, cabinet, or other opening will not receive tile, deduct width × height × quantity. The calculator subtracts openings before it calculates base tiles and waste. Do not deduct surfaces you still plan to tile, such as tiling up to a window stool or around a door frame.

Multiple Areas

Use a separate area for each rectangle: Room 2, a second wall, another shower face. The calculator adds those measured areas, subtracts openings, then calculates tiles. Combining first avoids rounding each small space into extra boxes on its own. See how many tile boxes you need for why that matters at purchase time.

Irregular and L-Shaped Spaces

The calculator doesn't calculate arbitrary polygon shapes directly. Divide an irregular or L-shaped area into rectangular sections and enter each section separately.

Rectangle A

10 × 12 = 120 sq ft

Rectangle B

6 × 8 = 48 sq ft

Combined area

168 sq ft

That combined area is what you use for how many tiles you need. Pattern complexity still affects suggested waste, not how you measure the rectangles.

Common Measurement Mistakes

• Mixing feet and inches incorrectly, or mixing Imperial and Metric.
• Measuring only one wall of a shower and ignoring the others.
• Forcing an L-shape into a single rectangle that is too large or too small.
• Deducting openings you still plan to tile.
• Using furniture placement instead of wall-to-wall dimensions.