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Methodology
Useful estimates start with visible assumptions.
Exact conversion. Practical purchasing.
We use the international foot: 1 ft = 0.3048 m and 1 in = 0.0254 m. One cubic yard is 27 cubic feet. One pound is 0.45359237 kg. One US liquid gallon is 3.785411784 L. A US short ton is 2,000 lb; a metric tonne is 1,000 kg.
Calculations retain physical values when switching units. Input text is rounded for readability, while the stored calculation value remains unchanged. Waste is applied once. Whole packages are rounded up at the end, with a small tolerance only for floating-point conversion noise.
Gravel
Area × loose layer depth = base volume. Add your allowance once. Divide cubic feet by 27 for cubic yards. Weight is volume × supplier bulk density; a US short ton is 2,000 lb.
Use the gravel calculatorFence
For each fence-only run, sections = round up(length ÷ maximum usable span). An open run needs sections + 1 posts. Gate endpoints are already included in adjacent runs. Concrete is cylindrical hole volume minus square post displacement.
Use the fence calculatorPaint
For a rectangular room, wall area = 2 × (length + width) × height. Subtract measured door and window areas. Multiply by coats and allowance, then divide by coverage per coat. Primer is calculated separately.
Use the paint calculatorMulch
Bed area × depth in feet = cubic feet. Multiply by (1 + allowance ÷ 100), divide by 27 for cubic yards, then divide by the printed bag volume and round up.
Use the mulch calculatorFlooring
Add the net areas of all rooms using the same product. Apply the allowance once to the total. Boxes = round up(adjusted area ÷ area per box). Cost = whole boxes × your price per box.
Use the flooring calculatorTile
Add the net areas that will receive the same tile. Each tile occupies its face size plus one grout joint in each direction: footprint = (tile length + joint) × (tile width + joint). Tiles = round up(net area × (1 + allowance ÷ 100) ÷ footprint). Boxes = round up(tiles ÷ tiles per box). Cost = whole boxes × your price per box.
Use the tile calculatorDrywall
Wall area = 2 × (length + width) × height. Subtract door and window areas, then add the ceiling (length × width) if it is being boarded. Sheets = round up(net area × (1 + allowance ÷ 100) ÷ sheet area). Joint compound and tape are estimated from net board area with editable rates. Screws scale with purchased board area: rate per 4 × 8 sheet × purchased area ÷ 32 ft².
Use the drywall calculatorWallpaper
Wall width to cover = room perimeter, or the width you measure. Openings are subtracted by area and converted back to width: net width = (width × height − openings) ÷ height. Strips needed = round up(net width ÷ roll width). Each strip is wall height + trim + pattern repeat, and strips per roll = round down(roll length ÷ strip length). Rolls = round up(strips including any allowance ÷ strips per roll).
Use the wallpaper calculatorRenovation budget
Line-item subtotal = materials + labor + permits & fees + fixtures & appliances + disposal & dumpster + other, using amounts from your own quotes and receipts. Sales tax = (materials + fixtures & appliances) × tax rate ÷ 100; labor, permits, disposal and other are not taxed here. Contingency = (subtotal + tax) × contingency rate ÷ 100. Total budget = subtotal + tax + contingency. Remaining to pay = total budget − already paid. Each category’s share is its amount ÷ subtotal. If you enter a ceiling, the difference is ceiling − total budget.
Use the renovation budget calculatorDefaults are assumptions
Gravel density is empty until you supply it. Paint coverage of 350 ft² per gallon, mulch bags of 2 ft³, flooring and tile allowances of 10%, concrete yield of 0.60 ft³, drywall compound at 1 US gal per 100 ft², tape at 37 ft per 100 ft², 32 screws per 4 × 8 sheet and wallpaper trim of 4 in per strip are editable planning examples, not universal specifications. The renovation budget’s 15% contingency is a planning assumption; HUD’s 203(k) rehabilitation program uses a 10–20% contingency reserve for comparison. Primer uses its own rate. Prices are entered by you.
References
Limits
Irregular geometry must be split into measurable areas. Quantity estimates do not determine structural adequacy, local code, plant needs or installation methods. Dimension and count limits reject unsupported project sizes rather than showing overflowing results.