HVAC Pro Calculator: NEC + P-T
BTU, Duct, P-T & Voltage
About
This app provides essential tools for HVAC technicians and electricians, including BTU load sizing, duct calculations, and refrigerant pressure-temperature charts. It offers a free tier with core functions and an optional Pro upgrade for advanced features like voltage drop calculations and unlimited job saving.
What's New in HVAC Pro Calculator
1.3.11
October 12, 2026
Wire sizing fixes in Voltage Drop. Aluminum wire is now sized from the NEC 310.16 aluminum ampacity column; before, it used the copper column and could pick aluminum wire one or two sizes too small. Small wire now follows the NEC 240.4(D) breaker limits (copper 14/12/10 AWG: 15/20/30 A; aluminum 12/10 AWG: 15/25 A), so a 22 A load gets 10 AWG copper, not 12. If you sized wire with an earlier version, please re-check it.
MoreSubscriptions & In-App Purchases
HVAC Pro Yearly
All HVAC calcs, unlimited saved jobs, PDF export.
Developer apps
FAQ
What is HVAC Pro Calculator?
HVAC Pro Calculator is a utility app designed for HVAC technicians and electricians. It offers tools for BTU load sizing, duct calculations, NEC voltage drop calculations, and refrigerant pressure-temperature charts, with formulas cited from industry standards.
Does HVAC Pro Calculator have ads?
No, HVAC Pro Calculator is ad-free. The developers emphasize that there are no ads, tracking, or upsell spam within the application, ensuring a clean user experience.
What are the pricing details for HVAC Pro Calculator?
The app offers a free tier with essential features. An optional Pro subscription is available for $9.99 per year, which unlocks advanced features like unlimited saved jobs and PDF export. A 3-day free trial is included with the yearly subscription.
What devices is HVAC Pro Calculator available on?
HVAC Pro Calculator is built for iPhone and iPad devices running iOS 17 or later. It supports Apple-native features like dark mode, Dynamic Type, and iPad split view.
How often is HVAC Pro Calculator updated?
The latest version of HVAC Pro Calculator is 1.2.0, which was last updated on June 17, 2026. Updates typically bring new features, improvements, and bug fixes.
Can I cancel my HVAC Pro subscription?
Yes, you can cancel your subscription at any time. Cancellations can be managed through your device's Settings > Apple ID > Subscriptions. The subscription auto-renews until canceled.
What is the age rating for HVAC Pro Calculator?
HVAC Pro Calculator has an age rating of 4+. This indicates it is suitable for users of all ages, with no content restrictions.
What makes HVAC Pro Calculator stand out from other trade apps?
Users appreciate that every formula is cited with its source (ASHRAE, NEC, SMACNA), providing accuracy. The app also features a field-readable, high-contrast design for sunlight readability and one-handed gloved typing.
