Formula reference library

Volume = surface area × depth
Weight = volume × material density

Volume = surface area × depth
(then converted to your chosen units)

Volume = surface area × depth
Weight = volume × selected material density

Markup % = (price − cost) ÷ cost × 100
Margin % = (price − cost) ÷ price × 100

Effective coverage = board width + gap
Board count = deck dimension ÷ effective coverage, then apply waste factor

Rectangular: length × width × average depth
Round: π × radius² × average depth
(then convert to requested units)

New pay = current pay × (1 + raise %)
Raise % = (new − old) ÷ old × 100

Panels = ceiling(length ÷ panel width)
Posts = sections + gate/corner/end adjustments

Pavers = project area ÷ paver face area, adjusted by the selected waste factor

Pitch = rise ÷ run
Angle = arctan(rise ÷ run)
Rafter length = √(rise² + run²)

Energy (kWh) = power (kW) × hours
Cost = kWh × tariff

Difference is computed date-to-date, preserving real month lengths and leap years
(not a simple 365-day average).

Overtime pay = overtime hours × hourly rate × multiplier
Gross pay = regular pay + overtime pay

Risers = round(total rise ÷ target riser height)
Treads = risers − 1 (typical)
Stringer length uses the Pythagorean relationship between total rise and total run