How our calculators work
Last updated: November 2026
Every calculator on housecosting uses the same small formula engine, so a rule is written once and checked once. The page shows the result for its default values, a worked example with each step, and a table of common sizes, all produced by that engine. Nothing you type leaves your browser.
Quantities
We measure area and volume with plain geometry (rectangles, circles, triangles, slopes), add the waste allowance shown in the form, and round up to whole units the way stores sell them: bags, sheets, boxes, bundles, rolls or quarter yards of ready-mix. Before a calculator goes live, its example is checked by hand; our test suite repeats those checks on every build.
Typical values we use
These are typical figures, not any brand's label. The bag, box or bundle you buy has the final word.
| Item | Value |
|---|---|
| Premixed concrete per bag | 40 lb: 0.3 cu ft; 50 lb: 0.375; 60 lb: 0.45; 80 lb: 0.6 |
| Normal-weight concrete | about 150 lb per cu ft |
| 8 x 16 in concrete block | 1.125 blocks per sq ft of wall |
| Modular brick, 3/8 in joints | 6.75 bricks per sq ft |
| Rebar weight per foot | #3 0.376 lb, #4 0.668 lb, #5 1.043 lb, #6 1.502 lb |
| Crushed stone base / sand | about 1.43 / 1.38 tons per cu yd |
| Compacted asphalt | about 145 lb per cu ft |
| Asphalt shingles | 3 bundles per square (100 sq ft) |
| Joint compound | about 0.9 gal per 100 sq ft of drywall, tape and two coats (a federal handbook lists 0.5; product guides 0.9 to 1) |
| Paint | about 350 sq ft per gallon per coat on smooth walls |
| Thinset, 50 lb bag | 1/4 x 1/4 in notch: 95 sq ft; 1/4 x 3/8: 65; 1/2 x 1/2: 45 |
| Insulation R per inch | batts 3.4, blown fiberglass 2.5, blown cellulose 3.5, XPS 5, polyiso 6 |
Costs: three lines
Materials are the quantity times the price you enter from your own supplier. We never copy store prices. Labor is hours times the median hourly wage for the trade in your state, from the U.S. Bureau of Labor Statistics (May 2025). The range uses the 25th and 75th percentile wages. These are wages paid to workers; a company's billed rate adds overhead, insurance and profit. Other items you can add, such as delivery, disposal or accessories.
Labor hours we start from
Most defaults come from the U.S. Navy's public construction estimating handbook (NAVFAC P-405), which plans crews at about two thirds efficiency, so experienced crews are often faster. You can scale the hours in each cost calculator. Access, tear-out, repairs and finish level change them a lot.
| Task | Hours | Basis |
|---|---|---|
| Place and finish concrete, per cu yd | 2.7 | Navy handbook table |
| Set and strip slab edge forms, per lin ft | 0.043 | Navy handbook table |
| Paver patio with base, per 100 sq ft | 12 | Our estimate (no public table) |
| Lay concrete block, per 100 blocks | 14.2 | Navy handbook table |
| Place asphalt, per ton | 0.5 | Our estimate (no public table) |
| Install asphalt shingles, per square | 5 | Navy handbook table |
| Tear off one layer, per square | 3 | Navy handbook, nearest task |
| Hang gutters, per 10 lin ft | 0.8 | Navy handbook table |
| Install vinyl siding, per square | 5 | Navy handbook, nearest task |
| Frame and deck, per 100 sq ft | 10 | Navy handbook (joists) + our estimate |
| Wood fence with posts, per 10 lin ft | 2.7 | Navy handbook table |
| Chain link fence, per 10 lin ft | 2.2 | Navy handbook table |
| Hang drywall, per 100 sq ft | 1.5 | Navy handbook table |
| Tape and finish drywall, per 100 sq ft | 1.8 | Navy handbook table |
| Blow attic insulation, per 100 sq ft | 1.5 | Navy handbook table |
| Install batts, per 100 sq ft | 1.5 | Navy handbook table |
| Paint walls, two coats, per 100 sq ft | 1 | Navy handbook table |
| Replace a window, each | 5.5 | Navy handbook table |
| Strip interior finishes, per 100 sq ft | 3 | Navy handbook table |
| Vinyl plank or laminate, per 100 sq ft | 3.3 | Navy handbook, nearest task |
| Set ceramic floor tile, per 100 sq ft | 24 | Navy handbook table |
| Install hardwood strip floor, per 100 sq ft | 8 | Navy handbook table |
| Install carpet, per sq yd | 0.45 | Navy handbook table |
Project benchmarks
Project cost pages show what U.S. households reported paying professionals for that type of job in the Census American Housing Survey 2023: the weighted median and the middle half (25th to 75th percentile), nationally and for the four Census regions, only where the survey has at least 50 jobs. We bring those amounts to current prices with the BLS Producer Price Index for construction materials, using 2022 as the base year (factor today: 1.109). It is a benchmark of real spending, not a quote for your house.
What the estimates leave out
- Structural design: we do not size footings, rebar, beams, joists or headers. Your local building code and a licensed professional decide those.
- Permits, inspections, delivery, equipment rental, disposal and repairs you find once work starts, unless you add them.
- Electrical and gas work, and hazardous materials such as asbestos or lead paint.
References for typical values and labor hours
- Federal Highway Administration: Portland Cement Concrete Testing Manual (unit weight of normal-weight concrete 140 to 150 pcf)
- Federal Highway Administration: FHWA-HRT-05-057, Appendix C (unit weights about 140 to 155 lb per cu ft)
- Naval Facilities Engineering Command, U.S. Navy: NAVFAC P-405 Seabee Planner's and Estimator's Handbook (Oct 1996), Table 4-55 Material Weights and Measures, p. 4-52 (gravel or limestone concrete 150 lb per cu ft)
- Concrete Masonry and Hardscapes Association (formerly NCMA): TEK 04-02A Estimating Concrete Masonry Materials (8/9 sq ft per unit; 119 units per 100 sq ft including 5 percent waste)
- Brick Industry Association: Technical Note 10, Dimensioning and Estimating Brick Masonry (Feb 2009), Table 4
- Texas Department of Transportation: 2024 Standard Specifications, Item 440 Reinforcement for Concrete, Table 1
- Concrete Masonry and Hardscapes Association (formerly ICPI): PAV-TEC-002-22 Construction of Interlocking Concrete Pavements
- Concrete Masonry and Hardscapes Association (formerly ICPI): PAV-TEC-025-22 Construction Guidelines for Segmental Concrete Paving Slabs and Planks in Pedestrian Applications (1 in compacted)
- Penn State University with the Pennsylvania Asphalt Pavement Association: Constructing Quality Asphalt Pavements Checklist Booklet 2025
- Tennessee Department of Transportation: Instructional Bulletin IB 16-16 (115 lb per sq yd per inch for one base mix)
- City of Shaker Heights, Ohio: Asphalt and Concrete Driveway Requirements (2 in surface course over 6 in aggregate base)
- Wisconsin Department of Transportation: Standard Detail Drawing SD 9A15 (driveway surface 2 to 3 in)
- Asphalt Roofing Manufacturers Association: Residential Asphalt Roofing Manual, Design and Application Methods, 2014 Edition, Chapter 5 and Glossary
- International Code Council: International Residential Code 2021, Section R806.2 Minimum vent area
- Asphalt Roofing Manufacturers Association: Attic Ventilation
- City of Hopkins, Minnesota: Gypsum Wallboard Fasteners (maximum fastener spacing table)
- International Code Council: International Residential Code 2021, Table R702.3.5 Minimum thickness and application of gypsum board
- Building America Solution Center, Pacific Northwest National Laboratory (U.S. DOE): Typical R-values and Vapor Retarder Classifications for Common Insulation Materials
- U.S. Department of Energy / Oak Ridge National Laboratory: Insulation Fact Sheet, DOE/CE-0180 (2008)
- Kansas Corporation Commission: PEP Fact Sheet: R-Values (2017)
- U.S. Department of Energy, Building Technologies Program: Energy Renovations: Insulation, A Guide for Contractors (2013)
- University of Missouri Extension: EM0104 Insulation (loose-fill fiberglass from R-2.2 per inch)
- U.S. Department of Energy, Building America: Which Spray Foam Is Right For You? (Building America, 2009)
- U.S. Department of Energy, Building America: Guide to Insulating Sheathing (Building America, 2007), EPS typically R-4 per inch
- ENERGY STAR, U.S. EPA and DOE: Recommended Home Insulation R-Values (based on 2021 IECC Table R402.1.3)
- Building America Solution Center, Pacific Northwest National Laboratory (U.S. DOE): 2009-2021 IECC and IRC Minimum Insulation Requirements for New Homes
- PaintCare Inc. (paint industry stewardship organization): Buy Right (paint coverage guidance)
- U.S. Environmental Protection Agency: Wall Paint Exposure Model (WPEM) Version 3.2 User's Guide (default 400 sq ft per gallon)
- USDA Forest Service, Forest Products Laboratory: Wood Siding: Installing, Finishing, Maintaining
- Purdue University Extension: NCR-135 Selection and Application of Exterior Finishes for Wood
- National Institute of Standards and Technology: Voluntary Product Standard PS 20-20, American Softwood Lumber Standard, Section 2.2 Board measure
- USDA Forest Service, Forest Products Laboratory: Wood Handbook, Chapter 5 Commercial Lumber (FPL-GTR-113), nominal 2 by 4 is 38 by 89 mm
- International Code Council: International Residential Code 2021, Section R311.7.5.1
- City of Escondido, California: Stairways, Guards and Handrails for Single Family Dwellings handout (7-3/4 in maximum riser)
- City of Ballwin, Missouri: Deck brochure (guards over 30 in above grade, 36 in minimum height)
- USDA Natural Resources Conservation Service: Conservation Practice Specification 382 Fence (Missouri, 20 in minimum)
- USDA Natural Resources Conservation Service: Conservation Practice Specification 382 Fence Woven (Kentucky 2024, 24 in minimum)
- USDA Natural Resources Conservation Service: Conservation Practice Specification 382 Fence Corral Lot (Illinois 2017, 3 ft line posts)
- ENERGY STAR, U.S. EPA and DOE: Room Air Conditioners, sizing chart
- U.S. Department of Energy, Energy Saver: Sizing a New Water Heater
Data sources and licenses are listed on the sources page. Questions or a mistake: [email protected].