Interior & Renovation Calculators
Paint, tile, flooring and drywall calculators — size the materials and estimate the cost for any interior or renovation project, fast and free.
CalcBooth’s interior calculators size the materials for a renovation room by room. The paint calculator works out how many gallons to cover the walls (and ceiling) for the number of coats you want, minus doors and windows. The tile calculator turns an area and a tile size into a tile count and boxes with the right waste allowance; the flooring calculator does the same for laminate, vinyl or hardwood by the box. The drywall calculator sizes sheets, joint compound, tape and screws for walls and ceilings, and explains the common thicknesses. Each tool shows the formula and adds a waste allowance so you buy the right amount the first time. These are planning estimates — confirm coverage and box sizes against your specific products before you buy.
Which calculator do I need?
| Calculator | What it works out |
|---|---|
| Paint Calculator | Find how much paint you need — enter your room size, ceiling height, number of coats and doors and windows to get the gallons of wall paint (and ceiling), with cost. |
| Tile Calculator | Calculate how many tiles you need — enter your area and tile size to get the tile count and number of boxes, with a waste allowance for cuts and breakage. |
| Flooring Calculator | Find how much flooring you need — enter your room size, the coverage per box and a waste allowance to get the square footage and number of boxes of laminate, vinyl or hardwood. |
| Drywall Calculator | Calculate how much drywall you need — enter your room size and sheet size to get the number of sheets plus joint compound, tape and screws, with a waste allowance. |
| Carpet Calculator | Work out how much carpet to order - enter the room size and the roll width to get the square yards off the bolt, the padding, tack strip and seam tape, plus a material cost estimate. |
| Carpet Installation Cost | Estimate what carpet installation costs - enter the room size, carpet price, labor rate and whether the old carpet has to come up to get an installed total, the cost per square foot and a full breakdown. |
| Blown-In Insulation Calculator | Work out how much blown-in insulation your attic needs - enter the area, what is already up there and your climate zone to get the depth to add, the volume, the bag count and what a professional install should cost. |
How these estimates are built
Every calculator in this category publishes the formula it runs, the constants it assumes, a worked example you can reproduce by hand, and the standard or manufacturer data sheet each constant comes from. Quantities include an adjustable waste allowance and round up to whole units, because you cannot buy part of a bag or box.
Cost figures are national US ranges and are material-only unless a calculator says "installed", so they exclude tax, permits and local labour rates. These are planning estimates, not quotes — read the full calculation methodology for what they cover, and the disclaimer for the structural and HVAC limits that apply.