How to measure
anything.

Step-by-step instructions for measuring rooms, walls, and spaces — so you always buy the right amount of material.

The Golden Rule

Always measure twice, calculate once. Add 10–15% overage to any material order to account for cuts, waste, and pattern matching.

Measuring a Room (Floor Area)

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Start by clearing the room of any large furniture that may be blocking the walls.

Measure the length of the room from wall to wall at its longest point, and write it down in feet and inches. Then measure the width from wall to wall at its widest point.

For rectangular rooms, simply multiply Length × Width to get your square footage. For L-shaped or irregular rooms, divide the space into separate rectangles, calculate each section individually, then add them together.

Finally, subtract any areas you don't need to cover — such as a built-in closet, fireplace hearth, or kitchen island base.

Tip: Use a laser measure for accuracy. Tape measures can sag on longer spans. For odd-shaped rooms, take a photo from above (standing on a chair) and sketch the outline.

Measuring Walls (for Wallpaper & Paint)

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Begin by measuring the height of the room from floor to ceiling. Then measure the perimeter by adding together the length of all four walls.

To find your total wall area, multiply the perimeter by the ceiling height. This gives you the gross square footage of paintable or wallpaperable surface.

Next, measure each door — a standard door is roughly 3 ft × 6.8 ft, or about 20 sq ft — and each window individually. For paint, subtract these openings from your total. For wallpaper, only subtract if the windows or doors are particularly large.

Tip: For wallpaper with a pattern repeat, add an extra 15–20% on top of the standard 10% overage to account for pattern alignment at seams.

Measuring for Tile (Floors & Walls)

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For floor tile, measure the room area as you normally would (length × width). For a backsplash, measure the width of the area and the height from the countertop to the upper cabinets — typically around 18 inches.

For a tiled shower, measure all three walls separately — the back wall and both side walls — then add them together. If the shower floor is also being tiled, measure that area separately and include it in your total.

Plan for 15% overage when laying tile on a diagonal, as angled cuts waste significantly more material. A straight layout only requires about 10%. Once you have your final square footage, divide it by the coverage listed on the tile box to determine how many boxes to purchase.

Tip: Buy all tile from the same dye lot. Tile colors can vary slightly between production runs — if you run short later, a new batch may not match.

Using a Floor Plan Photo

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Photograph or screenshot your floor plan so that any scale bar or labeled dimensions are clearly visible and the text is legible. If the plan includes a scale bar (for example, "1 inch = 10 feet"), make sure it appears in the frame.

Plans with labeled wall dimensions — such as "12'6"" written along each wall — work best, as the AI reads those numbers directly. If your plan is missing labels, add a note in the notes field explaining the scale or any room dimensions you already know.

Once your image is ready, upload it in the Calculator tab, choose your use case if applicable, and hit Analyze. Even a hand-drawn sketch will work well as long as the measurements are clearly written on each wall.

Tip: If you only have a rough hand sketch, write the measurements on each wall before uploading. Even rough sketches produce good results when the numbers are legible.

What can you calculate?

🪵

Hardwood & LVP Flooring

Calculate how many square feet of planks to order, including waste for cuts and borders.

sq ft × 1.10 = order qty

⬜

Floor & Wall Tile

Find out how many boxes of tile you need for floors, backsplashes, or full shower surrounds.

sq ft ÷ box coverage

🖼

Wallpaper

Calculate the number of rolls needed based on wall height, room perimeter, and pattern repeat.

wall sq ft ÷ 28 = rolls

🎨

Interior Paint

Estimate gallons needed for walls and ceilings. One gallon typically covers 350–400 sq ft per coat.

wall sq ft ÷ 375 = gallons

🟫

Carpet

Carpet is sold by the square yard. Convert your room area and add overage for seams.

sq ft ÷ 9 = sq yards

❄️

HVAC Sizing

BTU requirements for heating and cooling are directly based on square footage and ceiling height.

sq ft × 25 = BTU estimate

🧱

Insulation

Calculate batt or spray foam coverage needed for walls, attic, or crawlspace areas.

sq ft + 15% overage

🏡

Real Estate Listings

Verify or calculate the gross living area (GLA) of a home for listing accuracy or appraisal purposes.

finished sq ft only

🌿

Solar Panels

Roof square footage determines how many panels fit and the potential energy output of your system.

roof sq ft × 0.8 = usable

Upload a floor plan,get instant square footage.

Add your image here

How to measureanything.