Data guides
Side-by-side tables of the figures behind our calculators, copied from makers' data sheets and university extension guides, with every row linked to where it came from.
- Air Conditioner Size Chart: How Many BTU for Your RoomThe ENERGY STAR room air conditioner sizing chart, its adjustments for sun, people and kitchens, and the BTU size for common room sizes worked out from it.
- AWG Wire Resistance Chart, with Voltage Drop DistancesDC resistance per 1,000 ft and per km for copper and aluminum wire by AWG size, and how far each size can run before the voltage drop passes the usual limit.
- How Much Concrete Does a Bag Make? Yields and Bags per YardPublished yields for every common bag size of Quikrete and Sakrete concrete, the bags needed per cubic yard, and bag counts for small jobs.
- How Much Does a Sheet of Drywall Weigh? Weights by Thickness and BrandPublished weights for drywall from USG, Gold Bond, CertainTeed and Georgia-Pacific, by thickness, with what a 4x8 or 4x12 sheet weighs.
- Grass Seed Rates by Grass Type, From University ExtensionsSeeding rates for bluegrass, fescue, ryegrass, bermuda, zoysia and centipede from university extension services, side by side, for new lawns and overseeding.
- How Much Does a Cubic Yard Weigh? Gravel, Sand, Soil, Mulch and MorePublished weights per cubic yard for gravel, sand, soil, mulch, compost, crushed stone and concrete, loose and compacted, from state DOT and EPA tables.
- How Many Bricks or Blocks Does a Bag of Mortar Lay?Published yields for pre-mixed mortar and masonry cement from Quikrete, Sakrete and Spec Mix, side by side, with what each figure includes.
- How Many Bundles of Shingles Make a Square? By Brand and ProductBundles per square, coverage and shingle counts for Owens Corning, CertainTeed, IKO, TAMKO and GAF shingle lines, copied from each maker's data sheet.