BTU Calculator: AC & HVAC
Room Size & Unit Sizing
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Get the right AC unit the first time. No more guessing, no more sweating. Calculate BTUs for any room in seconds.
Size your AC or heating unit correctly - no more overpaying or sweating.
Takes room dimensions, ceiling height, insulation, sun exposure, occupants, and kitchen to recommend the right BTU and tonnage.
KEY FEATURES:
* Adjusted BTU Recommendation - Base BTU adjusted for conditions
* Tonnage Rating - Unit size in tons for HVAC shopping
* Adjustment Breakdown - How each factor affects BTU needs
* Imperial & Metric - Feet or meters; BTU or watts
* Multiple Factors - Insulation, sun, occupants, kitchen
Free to download. No sign-up. No paywall. Works offline.
By Blas Apps - simple calculators that do one thing perfectly.
Ratings & Reviews
Improved App Store listing.
The developer, Blas Prieto, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Blas Prieto
- Size
- 25.9 MB
- Category
- Utilities
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Blas Apps