Category: Calculators

A bathroom tile order often contains several products: floor tile, wall tile, perhaps a feature tile, and pieces for the edges. Adding all the areas into one number can hide the quantity you need of each.

Use this written worksheet to organize the order. Confirm the measured areas, layout, cutting allowance, and product suitability with the installer. It is not a tile assembly design or a waterproofing specification.

Make one line for each product and surface

For a rectangular surface, area is length × height or length × width. Add separate rectangles for an irregular shape without counting overlaps twice. Record openings and ask the installer which should be deducted given the actual layout. Small cuts around openings can still consume whole tiles.

Work the floor example

Assume a measured 60-square-foot floor, an installer-approved 15% allowance, and a hypothetical box covering 10 square feet. The preliminary order is 60 × 1.15 = 69 square feet. Divide by 10 and round up: seven boxes, supplying 70 square feet.

The allowance is an example input, not a universal tile rule. A diagonal layout, large tile, or a particular cut plan may need a different order. Keep any decision about spare pieces for future repair explicit so it is not accidentally counted twice.

Then work the wall example

Suppose three wall sections are 5, 4, and 5 feet wide, each tiled to 8 feet. Gross area is (5 + 4 + 5) × 8 = 112 square feet. If the installer confirms a 12-square-foot opening should be deducted, the net measured area is 100 square feet.

With an assumed 10% allowance, the target becomes 110 square feet. If this different tile covers 12 square feet per box, 110 ÷ 12 = 9.167 boxes, rounded up to ten boxes supplying 120 square feet. Do not combine this box count with the floor product before rounding.

Price the rounded quantities

At invented prices of $4 per purchased square foot for the floor tile and $5 for the wall tile, material costs are 70 × $4 = $280 and 120 × $5 = $600, totaling $880. This excludes trim, setting materials, preparation, installation, delivery, and tax. Those amounts belong in the complete project budget.

If the store prices by box, use the box price directly. A displayed per-square-foot price may be a comparison figure rather than permission to buy fractional boxes. Confirm pack sizes for decorative pieces as well.

Check the order before paying

• Are all products identified by exact model and finish?
• Has the installer approved the layout and quantities?
• Are trim pieces, corners, and edge details separately counted?
• What are the delivery inspection and return terms?
• What product and batch information should be kept?

Save the final order with the project documents. If you are supplying the tile yourself, use the responsibility checklist so receiving and replacement decisions are settled before the installation date.

Written with AI assistance. Sources and calculations checked September 8, 2026. How we prepare our guides. Questions or corrections: hello@homestria.com.

A cheaper gallon does not always make the cheaper room. The quantity you need depends on the area, coats, and coverage of the selected paint, followed by the container sizes you can buy.

Use this written worksheet to compare plausible product choices on the same surface. It is an arithmetic tool, not a test of hiding power, durability, or suitability. A product’s directions and the condition of the surface determine the inputs you should use.

Hold the room constant

Start with the paintable wall area from the room measurement guide. Keep ceilings and trim separate if they use other products. Decide which coats and any primer are required before treating two options as equivalent.

Gallons required = paintable area × coats ÷ coverage per gallon.
Purchase cost = sum of the selected container quantities × their prices. If only one-gallon cans are available, round gallons up to the next whole can. Other available sizes may give a different purchase combination.

A comparison with invented paint inputs

Assume 371 square feet of wall and two coats, giving 742 square feet of coverage to supply. Both hypothetical products are assumed suitable for this comparison. All prices and coverage values below are invented examples, not current product specifications.

Paint B costs $15 less for this example despite its higher price per gallon. That result depends on the assumed coverage and two-coat plan. It does not establish that a more expensive paint generally saves money.

Check a less favorable coverage assumption

If Paint B instead covers 250 square feet per gallon on the selected surface, the requirement becomes 742 ÷ 250 = 2.968 gallons. Buying three one-gallon cans at the same invented $60 price costs $180. Now it costs $45 more than Paint A in the original comparison.

Use the selected product’s label and advice appropriate to the surface rather than automatically choosing the highest coverage number. BEHR’s paint quantity guide gives context for why coverage assumptions affect a purchase. The example here is independent of any named paint line.

Add the items that the paint price leaves out

• Primer, calculated for its own area and coverage where required.
• Ceiling, trim, or door coatings kept on separate lines.
• Tools, protection, and preparation materials.
• Labor and repairs if you are hiring the work.
• Tax, delivery, and any container sizes actually available.

Do not compare an option that includes all those items with one that only prices wall paint. If a contractor includes coatings in the quote, avoid adding the same cans again. The interior painting budget shows the room-level structure.

Save the inputs with the final choice

Record the measured area, required coats, selected product, finish, label coverage, and purchase combination. When the room is done, move the product details into the paint record. That makes the worksheet useful for the next repaint as well as today’s trip to the store.

Written with AI assistance. Sources and calculations checked September 8, 2026. How we prepare our guides. Questions or corrections: hello@homestria.com.

A floor needs 531.3 square feet of material on paper, but the store sells cartons. The last step is to round the order to something you can actually buy—without quietly dropping the cutting allowance you added a moment earlier.

This is a written calculator guide. Use your room measurements, the allowance agreed with your installer, and the coverage printed on the exact carton. It does not measure the room or choose an installation allowance for you.

The formula

Cartons to buy = round up [measured area × (1 + allowance rate) ÷ coverage per carton]. Enter 10% as 0.10. Keep the area and carton coverage in the same units. Round up at the carton step rather than rounding away smaller quantities along the way.

Measure distinct sections and add their areas without counting overlaps twice. If the layout has fixed fixtures or unusual shapes, ask the installer which areas belong in the order. An approved cut plan matters more than an assumed percentage from a generic worksheet.

A 483-square-foot example

Twenty-one cartons would supply only 525 square feet, below the 531.3-square-foot target. Twenty-two cartons supply 18.7 square feet more than that target and 67 square feet more than the measured room. Those are different comparisons: some extra area was already part of the assumed allowance.

The 10% and carton size are example inputs, not a product recommendation. Replace both with the installer-approved allowance and the actual packaging. If the carton coverage changes, rerun the last two steps.

Calculate different products separately

Suppose two rooms use different colors with the same hypothetical 25-square-foot carton. Room A is 120 square feet and Room B is 180. At an assumed 10% allowance, A needs 132 square feet, or six cartons; B needs 198 square feet, or eight cartons. That is fourteen cartons across the two colors.

Combining the rooms first gives 300 × 1.10 ÷ 25 = 13.2, rounded to fourteen cartons, which happens to match here. It will not always match, and it cannot tell you the correct split between colors. Always calculate each distinct product or finish separately.

Keep order quantity out of the wrong cost line

If material is priced per purchased square foot, use the full 550 square feet in the first example. If installation labor is quoted per installed square foot, confirm the labor area with the installer rather than automatically billing the purchased amount. See the flooring budget example for separate material and labor lines.

• Record the measured area and who confirmed it.
• Save the exact model, carton coverage, and approved allowance.
• Check the cut plan, availability, and return terms before ordering.
• Keep the label information with the home record.

For tiled walls as well as floors, use the tile worksheet. Different surfaces and trim pieces need their own quantities even when they are part of one room.

Written with AI assistance. Sources and calculations checked September 8, 2026. How we prepare our guides. Questions or corrections: hello@homestria.com.

“Leave fifteen percent” sounds clear until you ask fifteen percent of what. A reserve added to the work budget is different from a reserve taken out of a fixed spending limit. Pick the calculation that matches your plan before comparing the numbers.

This written calculator guide uses hypothetical percentages to explain the formulas. It does not prescribe the right reserve for your home. That depends on the scope, known conditions, and risks you discuss with the people assessing the project.

If the base work is already priced

Reserve = base cost × reserve rate.
Total planned funding = base cost + reserve. For a $15,000 base and an assumed 15% reserve, multiply $15,000 × 0.15 = $2,250. Total planned funding is $17,250.

That reserve is money you hold for possible changes, not automatically extra money owed to the contractor. Keep it separate from the agreed contract unless your agreement explicitly treats it differently.

If your total spending limit is fixed

Base budget = total limit ÷ (1 + reserve rate).
Reserve = total limit − base budget. This formula uses a reserve that is a percentage of the base work.

The amounts are rounded to cents, with the reserve shown as the difference from the total. The 15% row means you should not commit $20,000 to the base work and expect another reserve to fit inside the same $20,000.

Why subtracting 15% gives a different result

Taking 15% directly from a $20,000 limit creates a $3,000 reserve and leaves $17,000 for base work. That is a valid budgeting choice, but the $3,000 is about 17.65% of the $17,000 base. Label it “15% of total” so nobody confuses it with “15% added to base.”

If you include taxes, delivery, or design fees in the base, do so consistently. A reserve should not conceal a known expense that you simply forgot to price. Put known items into the base and use the reserve for the uncertainty you intend it to cover.

Update the ledger after each approved change

Start with a hypothetical $12,000 contract and $2,000 reserve. Approve an $850 addition and a $200 credit: net increase $650. The revised contract is $12,650 and the remaining reserve is $1,350. Together they still represent $14,000 of planned funding.

Do not show $12,650 plus the untouched original $2,000 as though none of the reserve has been used. Record approved changes when they are committed, not only when the final invoice arrives. Our change-order guide supplies the fields to keep.

Choose what changes when the limit is reached

If the remaining reserve is no longer enough, identify the next decision explicitly: reduce optional scope, increase the approved funding if feasible, or get a revised plan. Do not treat a calculator’s positive balance as evidence that the remaining work is affordable when several items are still unpriced.

Use the bathroom budget guide to organize the base costs and the quote comparison sheet to keep allowances visible.

Before setting your reserve, check whether the base quote already covers debris removal, final cleaning, and disposal. Use the renovation cleanup quote checklist to identify these known costs; keep them in the base budget rather than counting on contingency to cover them.

Written with AI assistance. Original guide checked September 8, 2026; the reduced-scope budget example was added and checked September 15, 2026. How we prepare our guides. Questions or corrections: hello@homestria.com.