DIYCalcLab

Formulas, examples and sources

Estimating topics

These pages are the method, not the tool list. Each one states the formula, the waste figure its calculator uses, a worked example and its sources. Category hubs stay the full tool lists.

  • Concrete

    The volume method behind DIYCalcLab concrete calculators: formulas, NIST conversions, a cited 5% or 10% overrun, and examples that open in the tools.

    Concrete — rectangular volume, then cubic yards, cubic meters or bags. The long walkthrough is the concrete guide. The tool list is Concrete calculators.

  • Paint

    Wall area, coats and tin sizes for the paint calculators: US gallons, UK 5/2.5/1 L tins and AU 10/4/2/1 L tins. The room walkthrough is the paint guide.

    Paint — wall area, coats and tin sizes (US gallons and quarts; UK 5 / 2.5 / 1 L; AU 10 / 4 / 2 / 1 L). The room walkthrough is the paint guide. The tool list is Paint calculators.

  • Flooring

    How plank area becomes boxes, and why carpet uses roll width. Blank waste uses 7%, 12% or 15% by layout. Measuring steps stay on the flooring guide.

    Flooring — plank area to boxes, carpet by roll width, and linear trim. Measuring steps stay on the flooring guide. The tool list is Flooring calculators.

  • Tile

    Tile count, layout waste, grout and thinset. A blank waste field uses 10%, 12%, 15% or 20% by pattern. The longer essay is the tile guide.

    Tile — tile count, layout waste, then grout and thinset. The waste-factor essay is the tile guide. The tool list is Tile calculators.

  • Landscaping

    Area times depth for mulch and gravel, then bags or tonnes. Depths stay on the landscaping guide. Enter the supplier density when you have it.

    Landscaping — area × depth, then bags or tonnes. Depths stay on the landscaping guide. The tool list is Landscaping calculators.

  • Roofing

    The method behind the roofing calculators: footprint, pitch factor, squares and waste. The roofing category page is the tool list.

    Roofing — plan area, pitch factor, squares and product-specific accessory rolls. The tool list is Roofing calculators.

  • Drywall

    How wall and ceiling area becomes sheet counts, and where joint compound and insulation use their own coverage charts. Not a fire-rated assembly designer.

    Drywall — sheet count, then compound and insulation on their own charts. The tool list is Drywall calculators.

  • Decking

    How a deck length and width become board rows and a joist count from a spacing you supply. This page does not size spans, beams or footings.

    Decking — board rows from actual width and gap. Spacing is an input. The tool list is Decking calculators.

  • Masonry

    The face-plus-joint method for brick and concrete block, and how an 80 lb mortar bag’s published maximum becomes a bag count. Not a structural wall design.

    Masonry — bricks or blocks from face plus joint, then mortar bags. The tool list is Masonry calculators.