All Calculators
Browse our complete collection of free professional trade calculators. All tools are based on current industry standards.
Electrical Calculators
(10)Voltage Drop Calculator
Calculate voltage drop in electrical circuits based on wire gauge, length, and load current per NEC standards.
Wire Gauge Calculator
Determine the correct AWG wire gauge based on current, voltage drop limits, and distance per NEC Table 310.16.
Conduit Fill Calculator
Calculate conduit fill percentage based on wire count and sizes per NEC Chapter 9 Table 1.
Ampacity Calculator
Determine wire ampacity based on NEC Table 310.16 with temperature and conduit fill correction factors.
Electrical Load Calculator
Calculate total electrical load for residential or commercial buildings per NEC Article 220.
Breaker Size Calculator
Determine the correct circuit breaker size based on wire gauge and load current per NEC 240.6.
Transformer Sizing Calculator
Calculate the required transformer kVA rating based on load requirements.
Power Factor Calculator
Calculate power factor, real power, reactive power, and apparent power for AC circuits.
Ohms Law Calculator
Calculate voltage, current, resistance, or power using Ohm's Law (V=IR) and the power formula (P=VI).
Wire Resistance Calculator
Calculate the total resistance of a wire run based on gauge, length, and material per NEC Table 9.
HVAC Calculators
(10)BTU Calculator
Calculate heating and cooling BTU requirements based on room size, insulation, climate zone, and occupancy.
Duct Size Calculator
Calculate required duct dimensions based on CFM airflow requirements and maximum velocity.
Refrigerant Charge Calculator
Estimate refrigerant charge based on system capacity, line set length, and refrigerant type.
Heat Load Calculator
Calculate building heat load using a simplified Manual J method for residential HVAC sizing.
CFM Calculator
Calculate cubic feet per minute (CFM) airflow based on room volume and required air changes per hour.
Air Changes Per Hour Calculator
Calculate the number of air changes per hour (ACH) based on room volume and airflow rate.
Cooling Capacity Calculator
Calculate cooling capacity in tons of refrigeration based on BTU load and system efficiency.
HVAC Duct Pressure Calculator
Calculate static pressure loss in ductwork based on duct dimensions, airflow, and fitting count.
Humidification Calculator
Calculate humidification requirements based on space volume, desired humidity, and outdoor conditions.
Energy Efficiency Ratio Calculator
Calculate EER and SEER ratings for HVAC equipment to compare energy efficiency.
Plumbing Calculators
(7)Pipe Size Calculator
Calculate the required pipe diameter based on flow rate and maximum velocity per plumbing codes.
Water Pressure Calculator
Calculate water pressure based on elevation head, supply pressure, and friction losses.
Flow Rate Calculator
Calculate water flow rate based on pipe size, velocity, and pressure differential.
Drain Pipe Slope Calculator
Calculate the required slope for drain pipes based on pipe diameter per IPC requirements.
Water Heater Size Calculator
Determine the correct water heater tank size based on household size and peak demand.
Pipe Friction Loss Calculator
Calculate friction loss in pipes using the Hazen-Williams formula based on pipe material, size, and flow rate.
Water Supply Fixture Unit Calculator
Calculate total water supply fixture units (WSFU) for pipe sizing per IPC Table E103.3(2).
General Construction Calculators
(3)Concrete Calculator
Calculate the amount of concrete needed in cubic yards based on slab, footing, or column dimensions.
Paint Calculator
Calculate the amount of paint needed based on wall area, number of coats, and paint coverage rate.
Lumber Calculator
Calculate board feet and total lumber needed for your project based on dimensions and quantity.