Methodology
Every calculator on this site follows the same core approach: convert your measurements into a volume or count, add a waste percentage for real-world conditions, then round to how suppliers actually sell the material. The specifics — density, waste factors, unit conversions — vary by material, so each calculator's page shows its own breakdown alongside the result.
Material weights (used to convert volume to tons) are typical industry averages. Actual density varies with moisture, compaction, and exact material grade, so weight and cost figures are estimates — confirm with your supplier before ordering.
Gravel Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)) for paths around a bed, or trapezoid (average of the two parallel sides × width) for tapered driveways. That area is multiplied by depth to get the exact volume required, converted from cubic feet to cubic yards (27 ft³ per yd³). We add your selected waste percentage to that required volume to get the waste-adjusted volume — the actual amount of material to buy — and every other figure (weight, bags, and cost) is calculated from that same waste-adjusted volume, so they always agree with each other. The suggested order then rounds that waste-adjusted volume up to the nearest 0.1 yd³, since most suppliers sell gravel in small fractional-yard increments. Weight uses the selected gravel type's typical density — crushed stone, pea gravel, limestone, river rock, and decomposed granite all pack differently, from about 2,600 to 2,800 lb per cubic yard. Total cost multiplies that weight by your entered price per ton. For small orders, we also estimate the equivalent number of standard 0.5 ft³ bags, and show the waste-adjusted volume and weight converted to metric (m³ and kg).
Concrete Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)), or trapezoid (average of the two parallel sides × width). That area is multiplied by thickness to get the exact volume required, converted from cubic feet to cubic yards (27 ft³ per yd³). Your selected waste percentage is added to that required volume to get the waste-adjusted volume, and weight and bag count are both calculated from that same waste-adjusted volume — weight assumes standard concrete at approximately 150 lb per cubic foot, and the bag estimate assumes standard 80 lb bags of concrete mix, each yielding about 0.6 ft³ once mixed. Ready-mix trucks are typically ordered in quarter-yard increments, so the suggested order separately rounds the waste-adjusted volume up to the nearest quarter yard.
Mulch Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)) for a mulch ring around a tree, or trapezoid (average of the two parallel sides × width). That area is multiplied by depth to get the exact volume required, converted from cubic feet to cubic yards (27 ft³ per yd³). Your selected waste percentage is added to cover settling, uneven ground, and spillage, and weight and bag count are both calculated from that same waste-adjusted volume — weight assumes standard shredded bark mulch at approximately 500 lb per cubic yard (actual density varies with moisture and mulch type), and the bag estimate assumes standard 2 cubic foot bags. The suggested order then rounds that waste-adjusted volume up to the nearest 0.1 yd³ for bulk delivery.
Topsoil Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)), or trapezoid (average of the two parallel sides × width). That area is multiplied by depth to get the exact volume required, converted from cubic feet to cubic yards (27 ft³ per yd³). Your selected waste percentage is added to cover settling and uneven grading, and weight is calculated from that same waste-adjusted volume — approximately 2,200 lb per cubic yard for moist, screened topsoil (actual density varies with moisture content and soil composition). The suggested order then rounds the waste-adjusted volume up to the nearest 0.1 yd³ since most suppliers sell topsoil by the yard.
Paver Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)), or trapezoid (average of the two parallel sides × width) — then converted to square inches and divided by the footprint of a single paver to get the base paver count. We add your selected waste percentage to account for cuts along edges, borders, and breakage, then round up to the nearest whole paver. This estimate assumes a simple running or basket-weave layout without a border course, which may need extra full pavers.
Sod Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)) for a lawn ring around a driveway loop or bed, or trapezoid (average of the two parallel sides × width). We add your selected waste percentage to cover irregular edges, curves, and cutting around obstacles like trees and beds. Pallet coverage assumes approximately 450 square feet per pallet and large-roll coverage assumes approximately 10 square feet per roll, though exact coverage varies by sod farm and grass variety.
Fence Calculator
The fence run is divided into equal sections based on your post spacing, rounded up to the nearest whole section, which means the built fence may run slightly longer than the exact input length. Posts equal the number of sections plus one (for both end posts). Rails are the number of sections multiplied by rails per section. We add your selected waste percentage to the rail count to cover cutting waste and damaged pieces; pickets are not estimated since spacing and width vary widely by style.
Paint Calculator
Wall area is calculated as total wall length × height. This calculator does not automatically subtract doors and windows, so for more precision subtract roughly 20 ft² per standard door and 15 ft² per standard window from your wall length × height total. That area is multiplied by the number of coats, then divided by standard paint coverage of 350 ft² per gallon (actual coverage varies by paint brand, sheen, and surface texture). We add your selected waste percentage for cutting-in, touch-ups, and uneven surfaces, then round up to the nearest quart.
Deck Calculator
Deck area is length × width. Decking linear footage is the area divided by the board's actual face width, which approximates board count while ignoring the small gaps typically left between boards for drainage. We add your selected waste percentage for angled cuts, staggered seams, and defects, then convert to a board count assuming standard 12 ft boards. Joist count assumes standard 16 in on-center spacing across the deck's width, with joists running the full length — actual framing should be confirmed against local building code and span tables for your joist size and species.
Driveway Calculator
Area is calculated from the shape you select — rectangle (length × width), circle (π × radius²), triangle (½ × base × height), circular ring (π × (outer radius² − inner radius²)) for a circular loop driveway, or trapezoid (average of the two parallel sides × length) for a driveway that tapers between the street and garage. Base and surface layer volumes are calculated separately (area × depth in feet) and then summed to get the exact volume required, since driveways are typically built with a compacted crushed-stone base topped by a finer surface layer. That required volume is converted to cubic yards (27 ft³ per yd³), then your selected waste percentage is added to cover compaction, spillage, and uneven sub-grade. Weight and the suggested order are both calculated from that same waste-adjusted volume — weight assumes standard crushed aggregate at approximately 2,800 lb per cubic yard, and the suggested order rounds up to the nearest 0.1 yd³.