Kitchen Backsplash Calculator
Show the math
What Your Result Means
- Total Square Feet: the raw backsplash area before waste — this is the net coverage you need.
- Number of Tiles: includes your waste factor for cuts, breakage, and pattern matching — buy at least this many.
- Grout: estimated at ~1.5 lbs per square foot — actual amount depends on tile size, joint width, and grout type.
- Thin-set Mortar: estimated at ~4 lbs per square foot for standard 1/4-inch trowel application.
How This Calculator Works
The calculator converts your width and height from inches to square feet, applies a waste factor for cuts and breakage, then multiplies by the tiles-per-square-foot rate for your chosen tile size. Grout and mortar are estimated at ~1.5 lbs/sq ft and ~4 lbs/sq ft respectively based on standard 1/4-inch trowel and joint-width applications.
Quick Questions
What waste factor should I use?
10% is typical for straight layouts (subway tile in running bond). Increase to 15-20% for diagonal patterns, mosaics, or around outlets and windows. Add more if you're new to tiling — practice cuts and breakage add up.
How much extra tile should I buy?
Always buy at least the calculated amount, plus 10-15% extra. Dye lots vary between boxes, and broken tiles or regrets happen. Leftover tile is useful for repairs later.
Can I use this for floor tile too?
Yes, but note that floor installations typically use more mortar (thicker beds) and higher-quality grout. Use this as a baseline and add 20-30% extra material for floors.
What grout joint width is standard for subway tile?
Subway tile typically uses 1/16" to 1/4" joints. The calculator assumes average spacing; wider joints use more grout, narrower joints use less. Verify your chosen width and adjust material purchases accordingly.
How do I handle outlets and windows?
Measure around them or subtract their area from your total. Outlets require tile cuts; windows need edge trim. Account for extra waste on these sections and buy extra tile for practice cuts.
Sources
Method & review
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.