Blog

A 20 ft wall at 16 in on-center needs 16 field studs plus 4 studs per opening and 3 corner studs - about 31 studs total. Here is the full math for any wall size.

A 10x12 deck needs about 25 deck boards (5/4x6, 12 ft), 9 joists, 6 footings and 200 deck screws. Here is the full materials list with board, joist and footing math.

A Doug fir 2x10 at 16 in on-center spans 16 ft 5 in for floor loads. SPF spans about 10% less. Deck loads reduce span another 10%. Here is the full table.

A 200 sq ft patio costs $400-800 in materials for concrete, $1,200-2,400 for pavers and $1,400-2,800 for clay brick. Here is how to choose.

A 100 ft fence with 8 ft panels needs 13 panels and 14 posts (15 with one gate). Here is the math by panel width, gate count and fence type.

Most asphalt shingles come 3 bundles per square (100 sq ft). A typical 2,000 sq ft roof needs 66 bundles with 10% waste - here is how the math works.

Most 4x4 fence posts need 1-2 bags of 60lb concrete. The exact count depends on hole diameter, depth and post size - here is the math without the guesswork.

A 12x10 bedroom takes about 2 gallons for two coats. A whole-house repaint runs 8-12 gallons. Here is the gallons-per-room breakdown plus the math behind it.

Mulch goes on top, topsoil fills space, compost feeds plants. Use the wrong one in the wrong place and you will smother your plants or waste money. Here is which goes where.

Flow rate units look interchangeable, but they aren't. Here's how GPM, CFM, SCFM, m³/h and L/s actually relate, with conversion factors and the SCFM vs ACFM trap engineers run into.

Sizing a heat exchanger means solving A = Q ÷ (U × LMTD × F). This guide covers typical U values for common fluid pairs, the F correction factor for shell-and-tube geometries and three worked sizing examples.

The formula is molarity = (density in g/mL × 1000 × mass percent) ÷ molar mass. Worked examples for concentrated acids and a reference chart for common reagents.

Plan on 1/2 pound (225g) of raw meat per adult as a starting point, then adjust for the cut. Pulled pork needs more, fish needs less. Here's the full reference.

The rule is simple: reduce oven temperature by 25°F and cooking time by 20%. Here's a full reference table and tips for what works best in an air fryer.

Not all gluten-free flours swap 1:1 for regular flour. Here are the correct ratios for each flour type, how much xanthan gum to add and which flour works best for different recipes.

The standard ratio is 3/4 cup oil for every 1 cup butter, but the swap affects texture, flavor and structure differently depending on what you're baking.