The full index
All Calculators
45 free calculators across 11 categories. Every one shows its working, cites its standards, and handles the details most tools skip.
Concrete & Masonry
Volume, reinforcement and cost for slabs, footings and posts
Concrete CalculatorCubic yards for slabs, footings, post holes and steps, with bag counts and truck loads.Concrete Slab CalculatorHandles thickened edges and returns rebar linear feet or wire mesh sheet count.Rebar CalculatorGrid layouts with lap splices and edge cover included — the part most tools miss.Post Hole CalculatorRecommends the depth and diameter to dig from fence height and frost line, then the concrete.Concrete Bag CalculatorBag counts for 40, 50, 60 and 80 lb sizes, plus pallets and mixing water.Footing CalculatorSizes strip footings from the IRC table and checks the projection rule most tools ignore.Concrete Mix CalculatorOne-bag batch recipes with the dry-volume factor exposed rather than hidden.Deck Footing CalculatorWorks from tributary area rather than dividing deck area by the number of posts.Wire Mesh CalculatorAccounts for the ACI lap, so a 5×10 sheet covers 40 square feet and not 50.
Brick & Masonry
Brick, block and mortar, counted by real coursing
Landscaping & Garden
Bulk materials by the yard, the ton and the bag
Gravel CalculatorYards and tons for ten stone types, with the compaction allowance driveways actually need.Mulch CalculatorBeds and tree rings, bag counts for every size, and a bags-versus-bulk price check.Topsoil CalculatorLawns, beds and raised beds, with blend recipes and a settling allowance.Sand CalculatorSix sand types with moisture-adjusted density, and why damp sand takes up more space.Paver Base CalculatorICPI base depths including the six inches of base that must extend past every paver edge.Raised Bed Soil CalculatorSplits fill volume by recipe, with settling derived from how much compost the mix contains.Compost CalculatorApplication rates by job, and a mode that works backwards from a target percentage by volume.Soil CalculatorBeds and pots, with frustum geometry for tapered containers and settling by mix.Retaining Wall CalculatorBuries the base course properly, and flags the height that needs an engineer.Grass Seed CalculatorSpecies rates for new lawns and overseeding, adjusted for pure live seed.
Interior & Finishes
Paint, drywall and trim, counted the way they are installed
Paint CalculatorBuys gallons plus quarts instead of rounding up, and prices primer separately.Drywall CalculatorSheets, compound, tape and screws, counting walls and ceilings separately.Wallpaper CalculatorCounts rolls by whole strips, because pattern repeat changes the answer in steps.Baseboard CalculatorPlans the cuts wall by wall and compares every stock length on waste and joints.Insulation CalculatorChecks the R-value your zone needs against what the cavity can physically hold.
Tiling & Flooring
Cartons, grout and the cuts that decide how it looks
Energy & Solar
System sizing, output and what it really saves
Solar Panel CalculatorSizes from real derate factors, and shows why self-consumption beats system size.Electricity Cost CalculatorSeparates the fixed supply charge from usage, which is why your effective rate is higher.Cable Size CalculatorSolves both constraints, because on long runs voltage drop governs, not current.Solar Battery CalculatorSized by solar surplus as well as evening load, with the tiered federal rebate.STC CalculatorZone rating and deeming years, floored as the regulator actually creates certificates.BTU CalculatorSizes to climate and envelope, and shows why an oversized system is the worse mistake.
Pool & Water
Capacity, salt and chemical dosing
Area & Conversion
The measurements everything else starts from
Square Footage CalculatorAdd several shapes or subtract islands and closets — built for rooms that are not rectangles.Cubic Yards CalculatorAny area and depth to cubic yards, plus weight in tons and how many truck loads that is.Board Foot CalculatorWorks back from finished parts through surfacing loss and grade waste to rough footage.
Roofing
True roof area from the footprint, and what covers it
Fencing & Decking
Posts, rails and the concrete that holds them
Cost Estimators
Line-item pricing you can hold a bid against
Concrete Slab Cost CalculatorA line-item estimate with current pricing you can hold a contractor bid against.Driveway Cost CalculatorCompares five surfaces on install price and on cost per year of service — they rank differently.Asphalt CalculatorOrders by the compacted ton, without the compaction factor that double-counts.