Plumbing & HVAC

BTU Calculator

Estimate cooling or heating BTU requirements from room size, ceiling height, insulation, climate, and internal loads, then compare the result in BTU, tons.

CFM Calculator

Calculate cubic feet per minute airflow for HVAC ducts, exhaust fans, or ventilation from room volume and ACH, then compare practical fan sizes.

French Drain Calculator

Estimate French drain gravel fill, bulk gravel weight, bag count, material cost, perforated pipe, filter fabric, excavation volume, cleanout access.

Furnace BTU Calculator

Size a furnace by estimating the BTU output needed for your home based on square footage, climate zone, insulation level, and ceiling height.

Pipe Volume Calculator

Calculate the internal volume of a pipe or tube in gallons, litres, or cubic feet from pipe diameter and length.

Refrigerant Line Charge Calculator

Estimate whether an HVAC line set needs added or recovered refrigerant using liquid-line length, factory allowance, manual oz-per-foot overrides.

Sump Pump Sizing Calculator

Estimate sump pump size, target GPM/GPH, total dynamic head.

Water Velocity Calculator

Calculate water velocity in a pipe from GPM and actual internal diameter, then compare the result with hot-water and cold-water planning guidance.

Window Air Conditioner Size Calculator

Find the right window AC unit capacity in BTU for a room based on dimensions, sun exposure, occupancy, and insulation quality.