Make sense of your project measurements.
Find your surface or material, check the assumptions, then open the matching calculator.
Paint, primer & surfaces
Ceiling Paint vs Wall Paint: Separate the Inputs
Measure ceiling and wall area separately, then use each selected product's coverage, primer requirement, and tested coat count.
Do You Need Primer? Use the Surface and Product Instructions
Decide primer from the substrate, contamination, repairs, and selected coating system, then calculate it with its own coverage and coat inputs.
Exterior Paint for a 1,500-Sq-Ft House: Measure the Walls
Why floor area cannot determine exterior paint, and how to measure wall elevations, gables, openings, coats, and product coverage.
How Many Square Feet Does a Gallon of Paint Cover?
Paint coverage is a product-and-surface input, not one universal number. Use the selected label, visible assumptions, and sensitivity cases to plan gallons.
How Much Paint for a 10x10 Room
Turn a 10-by-10 room's perimeter and wall height into net paintable area, subtract measured openings, and size paint by coats and product coverage.
How Much Paint for a 12x12 Room?
Calculate paint for a 12-by-12 room from measured height and openings, selected-product coverage, and an explicit tested coat plan.
How Much Paint for a 2-Car Garage Interior
Measure garage walls, ceiling, and openings, then calculate each drywall or masonry coating from its selected product coverage and coats.
How Much Paint for a Bathroom
Measure a bathroom's real painted wall area around the tub, vanity, tile and mirror, then size a moisture-friendly paint by coats and coverage.
How Much Paint for a Gable or Vaulted Wall
Split a gable or vaulted wall into rectangles and triangles, subtract measured openings, and apply the selected coating's coverage and coats.
How Much Paint for a Stairwell
Measure a stairwell's tall, angled walls as rectangles and triangles, then size paint by coats and coverage — the access, not the math, is the hard part.
How Much Paint for an Accent Wall
Size paint for a single accent wall from its measured area, product coverage and tested coat plan, then round to available package sizes.
How Much Paint for Interior Doors and Trim
Estimate paint for doors and trim from door faces and linear feet of casing and baseboard — a small quantity that hides in a different measurement.
How Much Paint or Stain for Both Sides of a Fence
Measure the actual coated faces of panels, pickets, rails, posts, gates, and edges, then use the selected coating's published coverage.
How Much Stain for a Deck With Railings
Measure deck boards, steps, and railing faces separately, then apply the selected stain's coverage and coat instructions.
Kitchen Cabinet Paint Calculator: Doors, Drawers, and Frames
Calculate kitchen cabinet paint and primer from measured doors, drawer fronts, frames, panels, coat counts, and the selected products' coverage rates.
Leftover Paint Math: Packages, Storage, and Touch-Up Records
Calculate package remainder without inventing a touch-up rate, and keep product records, storage instructions, and local disposal rules with the paint.
Painting Over Dark Walls: Plan Coverage Without Guessing Coats
Separate spread rate from hiding, use the selected coating system and a test area to plan primer, coats, gallons, and package costs.
Flooring, boxes & overage
Calculating Tile for a Small Bathroom
Measure the actual tiled field, enter an explicit layout overage, and round using the selected tile or carton coverage.
Do You Need Underlayment? Read the Flooring System First
Determine underlayment and moisture-control requirements from the selected flooring instructions, then calculate rolls from the printed net coverage.
Flooring Two Rooms Continuously: Area and Transition Checks
Sum connected floor areas, verify the selected product permits the continuous run, enter a cut-plan overage, and round once by carton coverage.
How Many Boxes of Laminate for a 10x12 Room?
Calculate laminate boxes from measured area, an explicit project overage, and the exact square-foot coverage printed on the selected carton.
How Much Extra Flooring to Buy: Make Waste an Explicit Input
There is no universal flooring waste percentage. Use product instructions, room geometry, layout, box coverage, and editable sensitivity cases.
How Much Flooring for an L-Shaped Room
Split an L-shaped room into non-overlapping rectangles, sum measured area, enter a justified overage, and round by exact carton coverage.
Laminate Flooring for Stairs: Count Components, Not Waste
Measure stair treads and risers, verify an approved stair system, and count nosings and accessories as separate product-specific components.
LVP vs Laminate vs Engineered Hardwood: Quote Worksheet
Compare flooring systems with actual box, accessory, preparation, delivery, and labor quotes instead of unsupported national price ranges.
Mulch, soil & outdoor projects
Cost to Mulch a Yard Yourself: Compare Your Bag and Bulk Quotes
Compare bagged and bulk mulch from entered volume, depth, bag price, bulk price, delivery fee, and supplier increments—not regional price claims.
How Many Bags of Mulch Are in a Cubic Yard?
A cubic yard is 27 cubic feet. Divide 27 by the printed bag volume, then round the project order—not the conversion—to whole bags.
How Much Gravel for a Patio Base? Volume Before Supplier Conversions
Calculate compacted patio-base volume, then apply the project specification, supplier loose-volume factor, and supplier density without fixed universal allowances.
How Much Mulch for a Tree Ring? Annulus Math
Calculate mulch for a tree ring by subtracting the trunk-side opening, then convert the measured volume to the bag size sold by your supplier.
How Much Soil for a 4x8 Raised Bed
Exact volume math for a 4-by-8-foot raised bed, plus a source-based way to separate soil quantity from soil composition and supplier pricing.
Mulch Depth: Coverage Math and Site-Specific Guidance
Calculate bag coverage at any entered depth, then choose depth from mulch type, soil, plants, existing layer, and extension guidance.
Mulch Top-Up Amount: Measure the Existing Layer First
A mulch top-up is chosen target depth minus measured remaining depth. Calculate bags from that gap instead of assuming an annual one-inch refresh.
Topsoil vs Compost vs Garden Soil: Compare the Label First
Separate exact soil-volume math from product-name assumptions, and calculate a mix only after choosing a source-backed recipe for the site.
Material costs & planning
Worked examples are illustrative. Read our method and corrections policy.