How to Measure a Room for Tile
Accurate measurement is the foundation of every tile job. Whether your floor is a simple rectangle or has doorways, closets, and niches, breaking the space into manageable sections makes calculation straightforward.
Visualizing Room Breakdown
An L-shaped room is split into two rectangles. Measure each section separately, then add them:
Total area: 160 + 120 = 280 sq ft. Add your waste factor using the tile calculator.
Step-by-Step Measurement Process
1. Sketch Your Room Layout
Before you measure, draw a rough sketch of your floor plan. Mark doorways, windows, closets, niches, and any wall protrusions (like a kitchen island or a fireplace bump-out). You don't need to be precise—this is just a reference guide.
2. Break Irregular Shapes Into Rectangles
The key principle: every shape can be divided into rectangles. An L-shaped room becomes two rectangles. A room with a niche becomes a main rectangle plus a smaller rectangle. For each division:
- Imagine a line crossing the room that separates one rectangular section from another.
- Each section must have four sides at right angles (or as close as walls allow).
- Label each section clearly on your sketch.
3. Measure Each Rectangle
Use a steel tape measure, a laser measure, or a long straightedge. Measure corner-to-corner for length and width. For each rectangle:
- Measure the longest wall (length) in feet.
- Measure the widest wall (width) in feet.
- Record both measurements to the nearest 0.1 feet (about 1¼ inches), or round to the nearest inch.
- If using a laser measure, take readings from multiple points to ensure accuracy.
4. Calculate Square Footage for Each Section
Multiply length × width for each rectangle. For example:
- Section A: 20 ft × 8 ft = 160 sq ft
- Section B: 12 ft × 10 ft = 120 sq ft
- Total: 160 + 120 = 280 sq ft
5. Account for Doorways and Openings (Optional)
Doorways and openings are typically small (2.5–3.5 sq ft). If precision matters to you, measure the opening and subtract it. However, most professionals include the full room footprint because the difference is minimal and accounts for edge cuts and layout adjustments. The choice is yours—either approach is reasonable.
6. Enter Your Total Into the Calculator
Once you have your total square footage, use the tile calculator to add your waste factor (10–20% depending on pattern and cut complexity) and determine how many boxes you need.
Common Scenarios
| Scenario | How to Measure |
|---|---|
| Bathroom floor + small niche | Measure main bathroom (e.g., 8 ft × 6 ft = 48 sq ft). Measure niche separately (e.g., 2 ft × 1.5 ft = 3 sq ft). Total: 51 sq ft. |
| Kitchen with island | Measure the overall room as one rectangle. The island is a permanent fixture, so it is not counted. No subtraction needed. |
| Entryway leading to hallway | Divide at the doorway. Measure entryway and hallway as separate rectangles, then add. |
| Master bathroom with walk-in closet (tiling both) | Measure bath and closet as separate rectangles. Include both in your total if both will be tiled. |
| Wall tile for shower enclosure | Measure height and width of each wall section. For a 5 ft tall × 8 ft wide wall: 40 sq ft. Calculate each wall separately if angles differ. |
Pro Tips
- Measure twice. Take a second measurement to confirm, especially for large areas.
- Use whole numbers when possible. If your room is 10.2 ft, round to 10 ft for initial calculation, then verify with the calculator.
- Account for grout width. Grout seams don't significantly reduce your tile coverage, so measure the physical space, not accounting for grout lines separately.
- For angled or sloped ceilings, measure the widest and longest points you will tile. Your installer can adjust the pattern to fit.
- Wall tile heights: For a bathroom or kitchen backsplash, measure the height of the wall you are tiling, then multiply by the width. This is separate from floor tile.
Related Guides
- How Much Tile Do I Need? — Calculate final box quantities after measuring.
- Tile Waste Percentage Explained — Understand waste factors for different patterns and cuts.
- Tile Size Guide — Choose tile dimensions and how they affect your measurements.
- Bathroom Tile Estimating Checklist — Ensure you don't miss any walls or details in a full bathroom renovation.
Ready to calculate? Use the tile calculator to enter your room measurements and find how many boxes to order.
Frequently Asked Questions
Break the room into two or more rectangles. Measure each rectangle (length × width), calculate the square footage for each, then add them together. This method works for any irregular floor plan.
Doorways are small (typically 2.5–3.5 sq ft). In most cases, you can include the full room measurement and the doorway opening will have minimal impact on your total. If you prefer precision, subtract the doorway area, but the difference is negligible.
Include closets in your measurement if they will be tiled with the same material. Measure them as a separate rectangle and add to your total room area.
Treat a niche as a separate rectangle. Measure the depth (how far into the wall) and the width, then calculate that area. Add it to your main room area. For wall tile in a bathroom, this is particularly important.
Measure as if the walls were square. For very steep angles (under eaves, cathedral ceilings), measure the actual widest and longest points of the wall you will tile. Use those as length and width.
Either is fine. Measure consistently (all feet or all metres), then use the calculator to convert. Do not mix feet and metres in a single measurement.