Calculators

Each calculator runs in your browser and shows the formula it applies and where the formula comes from. Use them to size a job before you ask for quotes.

• Concrete calculatorCubic yards and bags for a slab, footing or post hole.
• Square footage calculatorArea of a room or lot, in square feet and metres, with material cost.
• BTU calculatorThe air conditioner size a room needs, from the ENERGY STAR chart.
• Voltage drop calculatorDrop on a copper or aluminium run, and the wire size that stays under 3%.