Measure run by run
Multiply each counter run by actual tile height to cabinet, shelf, or termination.
Add range, hood, side returns, and window returns separately.
Decide which openings to subtract
Large windows can reduce field area, while outlets usually create cuts without materially reducing purchases.
Use layout rather than subtracting every opening mechanically.
Account for the pattern
Running bond, herringbone, vertical stack, borders, and centered layouts produce different cuts.
Decide pattern and orientation before final ordering.
Convert to product packages
Use exact carton or sheet coverage and round up to full packages.
Trim, pencil, bullnose, profiles, and accents are separate takeoffs.
Verify setting-material coverage
Mortar, grout, sealant, and substrate preparation depend on selected system and conditions.
Use manufacturer coverage data rather than deriving them from tile boxes.