HVAC

HVAC Calculators

Manual J load estimates, duct sizing, CFM, refrigerant charge, and SEER savings. Based on ACCA Manual J, Manual D, and ASHRAE standards.

Made for HVAC techs

Five calculators for heating and cooling

From load estimates to duct sizing, these tools cover the math HVAC technicians use on every job.

Simplified heating and cooling load estimate. ACCA-inspired BTU sizing for residential systems.

Calculate duct area and round diameter from CFM and target air velocity per ACCA Manual D.

Estimate refrigerant charge for split systems based on capacity and line set length.

Calculate required airflow for a room from volume and air changes per hour (ACH).

Calculate annual energy savings from upgrading to a higher SEER system.

Estimates, invoices, scheduling, and payments in one place. Free to start.