Disclaimer

All results are planning estimates

The calculators turn your measurements into material quantities using documented formulas and stated assumptions (see the methodology page). They are designed to get your shopping list and budget close — not to produce construction documents. Your actual needs depend on site conditions, product choices, layout, and workmanship that no calculator can see.

No engineering advice

Nothing here sizes structural members or checks loads. Joist and beam spans, footing sizes and depths, and anything load-bearing must be verified against prescriptive code tables, your local building department, or a licensed engineer. Where a calculator shows framing quantities, it is counting pieces for shopping purposes, not designing a structure.

No electrical advice

The generator sizing tool is planning-level only: it adds up appliance wattages to suggest a capacity range. It does not design an electrical installation. Transfer switches, interlocks, and any connection between a generator and building wiring must be done by a licensed electrician — improper connections can backfeed the grid and kill utility workers.

Local codes and permits vary

Building codes, permit requirements, setback rules, and inspection practices differ by country, state, and municipality, and they change. A default in a calculator (like a footing depth used for volume math) is not a code requirement. Check with your local building department before you build.

Verify product specifications

Coverage rates, dimensions, and yields vary by manufacturer: a "6-inch" board is usually 5-1/2 inches wide, concrete bag yields differ between mixes, paint coverage depends on the surface, and flooring box coverage varies by product line. Check the label or spec sheet of the actual product you buy and adjust the calculator's assumptions to match.

When to bring in a professional

Professional review is appropriate — and often legally required — for structural, electrical, gas, and load-bearing work. If a project involves any of those, treat the calculator output as preparation for that conversation, not a replacement for it.

Safety warnings are informational

Calculators on this site surface safety reminders where relevant — calling 811 before digging, carbon-monoxide and generator precautions, and lead or asbestos cautions in older homes, drawing on guidance from agencies such as the CPSC and EPA (linked on the sources page). These warnings are informational and not exhaustive: they cannot cover every hazard on your site. Read and follow product instructions, use appropriate protective equipment, and stop and get help when something is beyond your experience.