Engineering Calculators

HVAC • Mechanical • Electrical — engineer-grade tools for daily work

Duct Size (CFM → Diameter) Duct Pressure Loss (Pa) Cooling Load (BTU/h) Filter Face Velocity ACH ↔ Airflow Converter Rect ↔ Round Equivalent Pump Head (m) Cable Voltage Drop
Tip: These tools are "engineering practical" — fast estimates with transparent formulas. You can extend tables and standards anytime.