HVAC Calculator Pro

What is HVAC Calculator Pro?

A free set of browser-based HVAC and electrical calculators with no registration. The homepage counts 51 tools: 20 HVAC calculators for heating and cooling load, boiler, radiator and duct sizing, pipe flow, pump head and expansion tanks, 20 electrical calculators for voltage drop, wire size, circuit breakers, conduit fill, motor current and power factor, and 11 unit conversion and energy tools. Each calculator comes with a guide that states the formula, the assumptions and a worked example, and the site also publishes reference tables, refrigerant pressure charts, design conditions by US city, and comparisons between ASHRAE, Chinese GB and Japanese SHASE methods. English, Chinese and Japanese versions are available, and the Chinese pages default to GB standards.

Record written 2026-10-07 from the vendor's submission and site. The about page says the site was founded in 2026 by an independent editorial team that claims no individual engineering credentials.

Key strengths

• 51 calculators across HVAC, electrical and conversion tasks, each with a calculation guide giving the formula, assumptions and a worked example
• the methodology page names the method behind each tool, for example Q = U x A x delta T for heating load, the continuity equation for duct sizing, Darcy-Weisbach with Colebrook for pipe flow, and EN 442 or GB/T 13754 for radiator output
• standards comparison pages set ASHRAE, GB 50736 and SHASE side by side for heating, cooling and duct sizing
• reference tables include breaker, MCA and MOCP charts, refrigerant PT charts for R-410A, R-32, R-22 and R-454B, and design conditions by US city
• English, Chinese and Japanese versions with region-appropriate default standards

Common use cases

Limitations to know

The vendor states that the results are preliminary estimates only and that final designs must be verified against local codes and professional engineering requirements, so nothing here substitutes for a stamped load calculation or an engineer's sizing. The cooling load tool uses a unit index method with corrections rather than a full room-by-room Manual J or RTS calculation. The methodology page says all calculations run in SI units internally, and the about page counts 49 calculators while the homepage counts 51, so the exact count depends on which tools are included. No company name beyond the site name, country, or team is published. AEC Hub has not tested the product.