Methodology and Sources
Our calculators provide transparent planning estimates, not guarantees. Area jobs use length × width or perimeter × height; volume jobs use area × depth. We apply the selected coverage, yield, coats and waste allowance, then round up to a unit you can buy. This page states where those figures come from, how a source is chosen, how often the numbers are revisited, and how to report one that looks wrong.
How a source is chosen
Each calculator is built from a documented reference, in this order of preference. Published standards and model codes come first, for example International Residential Code provisions, ASTM and ACI material standards and American Wood Council publications. Manufacturer data comes second, meaning the coverage charts, spread rates, yields and installation instructions printed on a product data sheet. Trade association and government agency references come third. Plain geometry comes last and is shown openly, because anyone can check area, volume, pitch and spacing by hand. Where two sources disagree we say so rather than hiding the range inside a single number, and we do not publish a figure we cannot attribute.
Unit conversion
Conversions between metric and imperial units follow the National Institute of Standards and Technology Office of Weights and Measures. The metric and imperial converter and the unit handling inside every other tool use those published factors rather than rounded shop conversions, because a rounded factor applied twice is how a slab ends up short by a wheelbarrow. Where a source publishes a figure in one system only, the original value is kept and the conversion is applied at the end.
How a page is checked before it publishes
A new calculator is written from its sources, then tested against a worked example calculated by hand and, where possible, against a real project quantity or a supplier takeoff. Edge cases are checked deliberately: zero and negative inputs, unit mix ups such as feet entered where inches are expected, very small areas and very steep pitches. Written guides are checked for factual accuracy, for statements that are specific to one region, and for anything that reads as professional advice when it should be a referral to a licensed professional. Nothing publishes until that pass is complete.
How often the numbers are revisited
Each page carries a published date and, once it has been revisited, a reviewed date. That date changes only when the content, the formula, the assumptions or the cost data actually changed; refreshing a date without doing the work is not acceptable here. Calculators tied to code requirements are reviewed after a relevant code cycle. Cost figures on the project cost calculator are gathered again on their own schedule and are stamped with the date they were collected. Everything else is reviewed at least once a year.
Reporting a figure that looks wrong
Send the page address, the values you entered, the result you got and the result you expected to bilgi@mydijital.com.tr. Reports are acknowledged, checked against the source, and either corrected or answered with the reasoning. A substantive change is logged with a date on the editorial policy and corrections page. The limits of every result are described in the disclaimer, and the contact page lists what else can be sent to us.
Reference list for every calculator
These are representative primary references behind the twenty tools listed in the tool index. Calculator pages carry their complete claim-level source lists; standards-owner, government, manufacturer and originating sector-organization material is preferred over summaries and aggregators.
- Paint Calculator: National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; U.S. Electronic Code of Federal Regulations, 40 CFR Part 59 Subpart D, Table 1: VOC Content Limits for Architectural Coatings; United States Environmental Protection Agency, Frequent question on the six square foot interior and 20 square foot exterior thresholds under the RRP Rule; PaintCare, Paint Calculators; United States Environmental Protection Agency, Renovation, Repair and Painting Program.
- Wall Area Calculator: National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity; Brick Industry Association, Technical Notes 10: Dimensioning and Estimating Brick Masonry; International Code Council, 2021 International Building Code, Chapter 10: Means of Egress.
- Tile Calculator: Daltile, Indoterra ColorBody Porcelain Floor and Mosaic Tile Sales Sheet; Tile Council of North America, ANSI Standards; Custom Building Products, SpeedSet Fortified Thin-Set Mortar Technical Data Sheet; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B9: Factors for Units Listed Alphabetically.
- Flooring Calculator: Pergo, How much flooring is required for my space?; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B9: Factors for Units Listed by Kind of Quantity; Building America Solution Center, Pacific Northwest National Laboratory, Wood Moisture Content.
- Concrete Calculator: The Quikrete Companies, Concrete Mix Product No. 1101 Technical Data Sheet; International Code Council, 2021 International Residential Code, Chapter 5 Floors; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.9 Factors for Units.
- Drywall Calculator: International Code Council, 2021 International Residential Code, Chapter 7 Wall Covering; Georgia-Pacific Gypsum, ToughRock Gypsum Board Submittal Sheet; Gypsum Association, GA-235-2019 Gypsum Board Typical Mechanical and Physical Properties.
- Wallpaper Calculator: Jupiter 10, Miles wallpaper product specification; Farrow and Ball, Calculating wallpaper quantities; Milton and King, Single Roll, Double Roll and Two Roll Set, What Does It Mean?; York Wallcoverings, How Much Wallpaper Do I Need?.
- Grout Calculator: Tile Council of North America, ANSI Standards; Custom Building Products, Prism Ultimate Performance Grout, Technical Data Sheet TDS-128.
- Mortar Calculator: Brick Industry Association, Technical Note 10: Dimensioning and Estimating Brick Masonry; Brick Industry Association, Technical Note 8: Mortars for Brickwork; Brick Industry Association, Technical Note 8B: Mortars for Brickwork, Selection and Quality Assurance; Ash Grove Packaging, Product Quantity Calculator and Masonry Quantity Charts; QUIKRETE, Mortar Mix No. 1102 Data Sheet.
- Decking Calculator: National Institute of Standards and Technology, Voluntary Product Standard PS 20-20, American Softwood Lumber Standard; American Wood Council, In the DCA6 you specify a live load = 40 psf. I thought the live load requirement for decks and balconies was 100 psf?; American Wood Council, Where can I get span tables and span table information for lumber? Where can I get decking span tables?.
- Fence Calculator: USDA Natural Resources Conservation Service, North Carolina, Conservation Practice Specification: Fencing, Code 382, Materials and Construction Specifications; International Code Council, 2012 International Residential Code, Appendix G Swimming Pools, Spas and Hot Tubs; International Code Council, 2015 International Residential Code Section R105.2, Work Exempt From Permit; USDA Natural Resources Conservation Service, New Mexico, Conservation Practice Standard: Fence, Code 382, New Mexico supplement.
- Roofing Material Calculator: Pennsylvania Department of Education, Carpentry Math T-Chart: Compute Roof Slope; International Code Council, 2021 International Building Code, Chapter 15 Roof Assemblies and Rooftop Structures; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.9 Factors for Units Listed by Kind of Quantity.
- Insulation Calculator: ENERGY STAR, US Environmental Protection Agency, Recommended Home Insulation R-Values; US Federal Trade Commission, Labeling and Advertising of Home Insulation: 16 CFR Part 460; US Department of Energy, Consumer Guide to Home Insulation, DOE/EE-2476; National Institute of Standards and Technology, Unit Conversion.
- Gravel Calculator: Federal Highway Administration, Granular Base, User Guidelines for Waste and Byproduct Materials in Pavement Construction; Federal Highway Administration, Planning an Unpaved Road Improvement Program, Unpaved Road Dust Management Handbook; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; United States Access Board, Guide to the ADA Standards, Chapter 3: Floor and Ground Surfaces.
- Mulch Calculator: United States Environmental Protection Agency, Composting At Home; Iowa State University Extension and Outreach, How to Determine the Amount of Mulch Needed for a Garden Bed; Clemson Cooperative Extension Home and Garden Information Center, Mulch, fact sheet HGIC 1604; Iowa State University Extension and Outreach, How deep should the mulch layer be around trees and shrubs?; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity.
- Garden Soil Calculator: University of Georgia Cooperative Extension, Raised Garden Bed Dimensions; University of Maryland Extension, Soil to Fill Raised Beds; United States Environmental Protection Agency, Composting at Home; NIST Office of Weights and Measures, Approximate Conversions from U.S. Customary Measures to Metric.
- Lumber Calculator: Rural Technology Initiative, University of Washington, Forest Products Measurements and Conversion Factors, Chapter 4: Lumber; USDA Forest Service, Forest Products Laboratory, Wood Handbook Chapter 6: Commercial Lumber, Round Timbers, and Ties (FPL-GTR-282); American Wood Council, Codes and Standards Publications.
- Waste-Factor Calculator: United States Environmental Protection Agency, Sustainable Management of Construction and Demolition Materials; National Institute of Standards and Technology, NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity; NIST Office of Weights and Measures, Unit Conversion.
- Metric-Imperial Converter: National Institute of Standards and Technology, NIST Special Publication 1038: The International System of Units, Conversion Factors for General Use; NIST Office of Weights and Measures, Approximate Conversions from U.S. Customary Measures to Metric; NIST Office of Weights and Measures, Approximate Conversions from Metric to U.S. Customary Measures; NIST Office of Weights and Measures, Unit Conversion.
- Project Cost Calculator: U.S. Small Business Administration, Calculate your startup costs; Tax Foundation, State and Local Sales Tax Rates, Midyear 2026; Federal Trade Commission, Buyer's Remorse: The FTC's Cooling-Off Rule May Help; Federal Trade Commission, How To Avoid a Home Improvement Scam.
Additional references used in the guides
Benjamin Moore, Paint Calculator for room dimensions, openings, and a two-coat planning estimate; Texas A&M 4-H, Housing and Home Environment for room measurement and home-project planning; Benjamin Moore, product FAQ for coverage, sheen, and drying context; Sherwin-Williams, paint preparation guide for manufacturer preparation guidance; U.S. EPA, remodeling indoor-air guidance for ventilation and pollutant-control practices; Tile Council of North America, movement-joint placement FAQ for movement-joint purpose and placement context. Complete claim-level citations remain visible on each guide page.
Important limitation
Product coverage, bag yield, package size, surface condition, temperature, humidity, layout and technique can all change the result. Verify the final quantity against the product label or technical data sheet before purchasing, and read the terms of use for the conditions that apply to everything published here.