🧰 ToolPicoAll Tools →

Paint & Tile Calculator

Find how many gallons of paint, boxes of tile, and boxes of flooring a room needs from its dimensions in square feet — with the standard 350-400 sq ft per gallon coverage rate, a built-in waste allowance, and an optional cost estimate. Square footage and whole-house modes included.

1 gal paint ~350-400 sq ft Tile waste ~10% Flooring box ~24 sq ft Updated: Jul 21, 2026
ft
ft
ft
I'll paint the ceiling tooCeiling area (length x width) is added to the wall area.
⚙️ Coats, coverage, waste & container size
sq ft
%
Coverage rate presets
$/gal
Enter a price per gallon to see an estimated total cost and cost per square foot.
ft
ft
Tile size (inches)
in
in
in
Added to tile pitch — directly changes tile count.
Layout pattern (sets waste)
⚙️ Box coverage and waste
sq ft
%
Box coverage is printed on the tile box (commonly 10-20 sq ft per box). Waste allowance still covers cutting/breakage on top of the grout-adjusted tile count.
$/box
Enter a price per box to see an estimated total cost and cost per square foot.
ft
ft
sq ft
Printed on the flooring box; typically 15-30 sq ft per box.
Layout pattern (sets waste)
⚙️ Waste allowance
%
8% for a straight layout; 10-14% for diagonal or herringbone.
$/box
Enter a price per box to see an estimated total cost and cost per square foot.
ft
ft
$/sq ft
Enter a per-square-foot price to see this area's estimated total cost.

Paint quantity for baseboard, crown molding, or door/window casing — measured as linear feet instead of square feet, since trim coverage is usually given per linear foot for a given profile width.

ln ft
Add up baseboard runs, crown molding runs, or door/window casing perimeters.
in
Trim type presets
⚙️ Coats, coverage & waste
ln ft
%
Coverage-per-linear-ft varies with profile width; a 3.5 in baseboard at ~200 ln ft/gallon is a common enamel/trim-paint estimate — check your can for the exact rate.
$/gal
Enter a price per gallon to see an estimated total cost.

Add each room, choose its type (paint / tile / flooring), and enter its dimensions in feet. The calculator totals paint gallons, tile boxes, and flooring boxes for the whole house and produces a combined shopping list. Fine-tuning (coverage, coats, tile size, box coverage, waste) uses each tab's standard defaults: paint 2 coats · 350 sq ft/gal · 5% waste, tile 24x24 in · 10% waste, flooring 24 sq ft/box · 8% waste.

Quick answer Gallons of paint needed = net wall area x number of coats / coverage rate. Standard interior paint covers about 350-400 square feet per gallon per coat (texture and surface porosity shift that range). For tile and flooring, divide the area (plus a waste allowance) by the box coverage printed on the box — a straight layout typically needs about a 10% waste allowance.
350-400sq ft per gallon (1 coat)
10%typical tile waste allowance
~24 sq fttypical flooring box coverage
2 coatsstandard interior paint job
⚙️ Accuracy & method note: Calculations use standard square-footage logic (paint: area x coats / coverage; tile/flooring: area x (1 + waste) / unit coverage). Coverage rate, coats, waste, and box/container size vary by product and surface — use the values printed on your specific paint can or box for a final purchase. Results are for informational purposes only; buying one extra can/box from the same batch is smart in case you need touch-ups later.
🎨 Paint & Tile Calculator — ToolPico ↗

How do you calculate paint, tile, and flooring quantities?

Every formula and worked example, from square-foot wall area to gallons of paint, tile pieces, and flooring boxes.

Square footage is the critical first step for any home-improvement project: buy too little and you may not be able to match the same paint tint or flooring batch later; buy too much and you've wasted money. This calculator handles paint, tile, and flooring the same way: first it finds the area, then divides that area by a coverage rate (gallons, tiles, or boxes), and finally adds a waste allowance on top.

How many gallons of paint do you need?

Quick answerGallons needed = net area x coats / coverage rate. Find the wall area (perimeter x ceiling height), subtract doors and windows, multiply by the number of coats, and divide by the coverage rate (350-400 sq ft/gallon per coat). For 285 sq ft of net area painted twice: 285 x 2 / 350 = 1.63 gallons. Add a 5-10% waste allowance and round up to whole containers.
  • Wall area = 2 x (length + width) x ceiling height, all in feet.
  • Net area = wall area - (number of doors x ~20 sq ft) - (number of windows x ~15 sq ft).
  • Gallons = net area x coats / coverage rate (sq ft per gallon).
  • Containers = round up(gallons / container size).

How many square feet does one gallon of paint cover? (coverage rate)

Quick answerStandard interior latex/acrylic paint covers about 350 to 400 square feet per gallon in a single coat on primed drywall. Textured, porous, or unprimed surfaces reduce that to roughly 250-300 sq ft/gallon; using a primer first restores the topcoat's normal coverage rate. Always check the exact coverage/coverage-rate value printed on your specific paint can.

How do you calculate tile needs?

Quick answerFind the area, add a waste allowance, and divide by the area of one tile. Tile count = area with waste / ((tile length in / 12) x (tile width in / 12)). Box count is that same waste-inclusive area divided by the square footage one box covers. For 200 sq ft of floor with 24x24 inch (4 sq ft) tile at 10% waste: 220 sq ft, so ~55 tiles, and at 15 sq ft/box that's ~15 boxes.

How many boxes of flooring or laminate do you need?

Quick answerBoxes needed = area x (1 + waste) / sq ft per box. Flooring and laminate boxes usually cover 15-30 sq ft (commonly around 20-24 sq ft). For 200 sq ft with an 8% waste allowance: 200 x 1.08 = 216 sq ft; at 24 sq ft/box that's 216 / 24 = 9 boxes. Raise the waste allowance to 10-14% for diagonal or herringbone layouts.

How do you find wall area?

Quick answerWall area = 2 x (length + width) x ceiling height. A 12 x 10 ft room with an 8 ft ceiling: 2 x (12 + 10) x 8 = 352 sq ft. For paint, subtract doors (~20 sq ft each) and windows (~15 sq ft each) to get the net paintable area. If you're painting the ceiling too, add length x width (120 sq ft in this example).

How much waste allowance should you add?

Quick answerWaste (cut-loss) allowance is a safety margin for touch-ups, cutting, and breakage. Use 5-10% for paint, about 8-10% for tile/flooring laid in a straight grid, and 10-15% for diagonal or herringbone layouts. Small, oddly-shaped rooms need more cuts, so lean toward the higher end. It's also smart to keep one extra can or box from the same batch for future repairs, since matching the exact tint or dye lot later can be difficult.

Paint examples by room size (2 coats, 350 sq ft/gallon)

Approximate paint needed with a standard 8 ft ceiling, 1 door and 1 window subtracted, 2 coats, and a 5% waste allowance. Use the calculator above for an exact figure.

Paint needed by room size (walls, 8 ft ceiling, 2 coats, 5% waste)
Room sizeNet wall areaPaint neededSuggested purchase
10 x 10 ft~285 sq ft~1.7 gal2 x 1 gal
12 x 10 ft~317 sq ft~1.9 gal2 x 1 gal
12 x 12 ft~349 sq ft~2.1 gal3 x 1 gal
14 x 12 ft~381 sq ft~2.3 gal3 x 1 gal
14 x 14 ft~413 sq ft~2.5 gal3 x 1 gal
16 x 14 ft~445 sq ft~2.7 gal3 x 1 gal

Popular ready-made calculations

Reference tables & practical figures

Paint coverage rates, common tile sizes, flooring box coverage, and recommended waste allowances.

Approximate coverage by paint type (single coat)
Paint typeCoverage (sq ft/gal)Note
Interior latex/acrylic350 - 400 sq ftMost common; 2 coats recommended
Ceiling paint300 - 350 sq ftUsually flat white
Primer250 - 300 sq ftReduces absorption, 1 coat
Exterior siding250 - 300 sq ftVaries with surface
Enamel/trim paint350 - 400 sq ftDoors, trim, radiators

Values are representative; the exact coverage rate is printed on the product can.

Common tile sizes and tiles per square foot
Size (in)1 tile (sq ft)Tiles per sq ft
8 x 80.44 sq ft~2.25
12 x 121.00 sq ft1.00
13 x 13~1.17 sq ft~0.85
18 x 182.25 sq ft~0.44
24 x 244.00 sq ft0.25
24 x 48 (plank)8.00 sq ft0.125
32 x 32~7.11 sq ft~0.14

Box coverage (sq ft/box) varies by manufacturer; use the "sq ft/box" value printed on the box.

Flooring box coverage examples and boxes for a 200 sq ft room (8% waste)
Box coverage200 sq ft (8% waste)Typical product
15 sq ft/box15 boxesNarrow plank / 8mm
20 sq ft/box11 boxesCommon laminate
24 sq ft/box9 boxesStandard flooring
30 sq ft/box8 boxesWide plank

Box counts are rounded up; keep any leftover material for future repairs.

Recommended waste allowance by job type
JobRecommended wasteWhy
Paint (flat wall)5% - 10%Touch-ups and loss
Tile (straight layout)8% - 10%Cutting and breakage
Tile (diagonal/patterned)10% - 15%More cutting
Flooring (straight)8%End cuts
Flooring (diagonal)10% - 12%Angled cuts

Keep waste near the higher end of the range for small or oddly-shaped rooms.

Add this calculator to your site (embed code)

Embed the paint & tile calculator on your own website for free. Copy the code below into your HTML — the tool runs in a simplified view and links back to this page as its source.

The embedded tool has a fixed layout; you can adjust the height value to fit your site. No ads or personal data, runs entirely client-side.

Paint, tile & flooring glossary

Short definitions of the core terms used in this calculator.

Coverage rateHow many square feet one gallon of paint covers in a single coat. Standard interior paint: ~350-400 sq ft/gal.
CoatsHow many times paint is applied to a surface. Usually 2; dark or poorly-covering colors may need 3.
Net paintable areaThe total area to be painted minus areas that aren't painted, like doors and windows.
Waste (cut-loss) allowanceThe extra percentage added to cover cutting and breakage. ~5-10% for paint, ~10% for tile, ~8-14% for flooring.
Tile sizeA tile's length x width in inches. One tile's area = (length/12) x (width/12) square feet.
Box coverage (tile)The square footage one box of tile covers. Box count = waste-inclusive area / this value.
Box coverage (flooring)The square footage one box of flooring/laminate covers, typically 15-30 sq ft.
PrimerA base coat applied before paint that reduces absorption on porous or new surfaces, lowering topcoat usage.
Baseboard/trimThe strip covering the floor-to-wall joint; its total length equals the room's perimeter.
Square footageAn area unit: length x width, both in feet. Wall, floor, and ceiling areas are all expressed in square feet.
Linear feet (trim/molding)The total run length of baseboard, crown molding, or casing, measured in feet along the trim rather than as an area.

In-depth guides

Detailed answers to the most common home-improvement measurement questions.

How many gallons of paint should I buy for my living room?

For a 16 x 14 ft living room with an 8 ft ceiling, the wall area is 2 x (16 + 14) x 8 = 480 sq ft. Subtracting 1 door (~20 sq ft) and 2 windows (2 x 15 = 30 sq ft) leaves a net area of 430 sq ft. At 2 coats and 350 sq ft/gallon coverage: 430 x 2 / 350 = 2.46 gallons; with a 5% waste allowance, about 2.58 gallons.

In practice, that means 3 one-gallon cans (or one 1-gallon can plus a quart, if your store sells that size) usually covers it comfortably. If you're also painting the ceiling (16 x 14 = 224 sq ft), add roughly another 1.3 gallons of ceiling paint — check the "I'll paint the ceiling too" box above to see both combined in one estimate.

How many boxes of tile do I need for a 200 sq ft bathroom?

For 200 sq ft of floor tiled with 24x24 inch tile (4 sq ft each), a 10% waste allowance brings the area used in the calculation to 220 sq ft. Tile count is 220 / 4 = 55 tiles; at 15 sq ft of coverage per box, that's 220 / 15 = ~15 boxes.

If you're also tiling the walls, calculate that square footage separately and repeat the same steps. Bathrooms and other wet areas with lots of cuts (around fixtures, corners) are safer with a 12-15% waste allowance so you don't run short mid-job. Add thinset mortar and grout to your shopping list too — the calculator's shopping list includes rough estimates for both.

Should flooring go in before or after painting?

As a rule, paint first, then install flooring — this keeps paint drips and drywall dust off a brand-new floor. If the subfloor needs leveling or repair, that rough work should still happen before painting; only the final coat of paint should come last, right before the finish flooring goes down.

When budgeting, run both the wall paint and the floor area through this calculator so you have a full material list and total square footage before you start buying. Keeping one extra box of flooring and one extra can of paint from the same batch on hand makes future touch-ups and repairs much easier, since matching the exact color or dye lot later can be difficult.

Frequently asked questions

How many gallons of paint do I need?
Gallons needed = net area x number of coats / coverage rate. Find the wall area, subtract doors/windows, multiply by the number of coats, and divide by the coverage rate (typically 350-400 sq ft/gallon per coat). For example, 285 sq ft of net area painted twice at 350 sq ft/gallon needs 285 x 2 / 350 = 1.63 gallons. Add a 5-10% waste allowance and round up to whole containers.
How many square feet does one gallon of paint cover?
Standard interior paint covers roughly 350-400 square feet per gallon in a single coat on primed drywall. Textured, porous, or unprimed surfaces reduce coverage, sometimes to 250-300 sq ft/gallon. Using a primer first restores the topcoat's normal coverage. The exact value is printed on your paint can.
How do you calculate tile needs?
Find the area, add a waste allowance, and divide by the area of one tile: tile count = area with waste / ((length in / 12) x (width in / 12)). Box count is that same waste-inclusive area divided by the box coverage in sq ft. For 200 sq ft with 24x24 in tile (10% waste, 15 sq ft/box), you need ~55 tiles, ~15 boxes.
How many boxes of flooring or laminate do I need?
Boxes needed = area x (1 + waste) / sq ft per box. Boxes typically cover 15-30 sq ft (often ~20-24 sq ft). For a 200 sq ft room with 8% waste: 200 x 1.08 = 216 sq ft; at 24 sq ft/box that's 9 boxes. Raise waste to 10-14% for diagonal or herringbone layouts.
How do you find the wall area of a room?
Wall area = 2 x (length + width) x ceiling height. A 12 x 10 ft room with an 8 ft ceiling: 2 x (12 + 10) x 8 = 352 sq ft. For paint, subtract doors (~20 sq ft) and windows (~15 sq ft) to get the net paintable area. Add length x width if you're painting the ceiling too.
How much waste allowance should I add?
Waste (cut-loss) allowance is a safety margin for cutting and breakage. Use 5-10% for paint, about 8-10% for tile/flooring laid straight, and 10-15% for diagonal or herringbone layouts. Small, oddly-shaped rooms need more cuts; keeping an extra can or box from the same batch is smart for future repairs.
Is the ceiling calculated separately from the walls?
Ceiling area = room length x room width and it's added to the wall area if you check "I'll paint the ceiling too" in this calculator. Ceilings are usually painted with a separate flat white ceiling paint but with a similar coverage logic, so they're easy to combine into one gallon estimate.
How many paint containers should I buy?
Divide the gallons needed by the container size and round up: containers = round up(gallons / container size). For 1.9 gallons, two 1-gallon cans (or 1 gallon + 1 quart) usually covers it. Jobs over about 4-5 gallons are typically more economical with a 5-gallon bucket instead of several 1-gallon cans.
How do you calculate paint, tile, and flooring cost?
Material cost = quantity needed x unit price. Enter the optional 💰 price field on each tab — price per gallon for paint, per box for tile, per box for flooring (or per sq ft on the square-footage tab) — and the result card automatically shows an estimated total cost in USD and a cost per square foot. Leave it blank and no cost is shown.
How much extra tile or flooring do diagonal or herringbone layouts need?
Diagonal and herringbone layouts require more cuts, so the waste allowance rises. Selecting a layout pattern in the tile or flooring tab auto-sets the waste percentage: ~10% straight / 12% diagonal / 15% herringbone for tile, and ~8% straight / 11% diagonal / 14% herringbone for flooring — so you see the resulting box count without adjusting waste by hand.
Can I calculate materials for my whole house at once?
Yes — the 🏠 Whole House tab lets you add rooms one at a time with a type (paint/tile/flooring) and dimensions; the calculator totals paint gallons, tile boxes, and flooring boxes across every room and produces a combined shopping list. Share the result with Copy link — the rooms are stored in the link.
Does grout gap width change how much tile I need?
Yes. Grout joints add real width to every tile's footprint, so a wider gap means fewer tiles fit per square foot. The 🧱 Tile tab has a grout gap width field that recalculates the effective tile pitch — (tile length + gap) x (tile width + gap) — directly, instead of only relying on a flat waste percentage.
How much paint do I need for baseboard, crown molding, or door casing?
Trim paint is usually sized by linear feet, not square feet, since coverage-per-linear-foot already accounts for a given profile width. The 🖼️ Trim & Casing tab uses gallons = linear feet x coats / (linear ft per gallon), plus a waste allowance — enter your total baseboard, crown molding, or door/window casing run length and pick a trim-width preset to get a gallon and container estimate.
Can I see results in metric units (m², liters, cm)?
Yes — the US / Metric toggle above the calculator switches every tab's result summary to square meters for area, liters for paint volume, and centimeters for tile and grout dimensions, using the same underlying calculation. Toggle back to US units (sq ft, gallons, inches) any time.

Methodology & sources

ToolPico's Paint & Tile Calculator is a free, independent tool. The calculation engine applies standard square-footage logic directly: paint gallons = net area x coats / coverage rate, net area = 2 x (length + width) x height - doors/windows; tile piece count = waste-inclusive area / tile area and boxes = waste-inclusive area / box coverage; flooring boxes = waste-inclusive area / box coverage. Waste allowance, coat count, coverage rate, and box/container size are all user-adjustable. Results are rounded up to whole boxes/containers.

Sources & assumptions: standard interior paint coverage ~350-400 sq ft/gal (single coat) · standard door ~20 sq ft, window ~15 sq ft · common tile sizes (8x8 to 24x48 in) · flooring box coverage 15-30 sq ft · recommended waste allowances 5-15%. Values are representative; the exact quantity depends on the coverage/capacity information on your specific product's packaging and surface condition. Last updated: July 21, 2026. Results are for informational purposes only and don't replace the manufacturer's label or a contractor's on-site measurement.

🔗 Add this tool to your site

Copy the code below into your own site. The tool is free, always up to date, and runs entirely on your page. No sign-up required.

Preview →
⚡ Built with ToolPico · toolpico.com