BaseCalc HVAC Calculator
BTU CFM Duct Calculator
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
HVAC field math for BTU, CFM, duct sizing, psychrometrics, manufacturer-data checks, saved history, worksheets, and materials. Pay once for Lifetime Pro — no ads.
BaseCalc HVAC Calculator is an HVAC calculator for field math, worksheets, materials, and saved calculation history. Run BTU, CFM, duct sizing, airflow, psychrometrics, manufacturer-data refrigerant checks, planning load, hydronics, and other HVAC calculator arithmetic on site, then save the result for the job.
18 CALCULATORS FOR DAILY FIELD WORK
• BTU ↔ Tons — convert between BTU/hr and refrigeration tons.
• CFM from BTU — airflow from load and temperature rise/drop.
• BTU from CFM — load from airflow and temperature difference.
• Duct Sizing — round and rectangular duct from CFM and velocity.
• Air Velocity — velocity from CFM and cross-sectional area.
• Psychrometrics — total, sensible, and latent BTU/hr estimates at standard atmospheric pressure.
• Refrigerant Lines — check entered manufacturer line data against an entered equivalent-length limit.
• Superheat / Subcooling — record the exact target supplied by the equipment manufacturer.
• Room Load — preliminary area-factor planning math using your supplied factor; not Manual J.
• Heat Pump Balance — interpolate a bracketed balance point from entered manufacturer capacity data.
• Hydronics — BTU, GPM, and ΔT relationships.
• Mixed Air — mixed-air temperature from outdoor and return air.
• Air Changes — ACH from CFM and room volume.
• Evaporative Cooling — supply temperature and sensible air-side estimate.
• Filter Velocity — filter face velocity; use manufacturer data for pressure drop.
• O₂ Excess Air — theoretical dry-flue-gas dilution estimate from measured O₂; not a safety result.
• Refrigerant Weight — additional charge from an entered manufacturer allowance and rate.
• Outdoor Airflow — breathing-zone airflow arithmetic from user-supplied per-person and per-area rates.
EVERY RESULT IS EXPLAINED
• Explicit input validation, assumptions, and calculation boundaries.
• Final arithmetic and a calculation breakdown where the supplied data supports one.
• Saved local history so you keep a job-site record.
JOB RECORDS, MATERIALS, AND WORKSHEETS
• Save job contacts with site notes.
• Build job worksheets with scope, quantities, and site notes.
• Export worksheet PDFs for internal handoff or customer context.
• Plan common pull-list items before rough-in, service, and closeout.
• Send the finished billing handoff to SpeakSheet for the final invoice.
DEVICE-LOCAL FOR THE FIELD
• Works offline by default.
• No BaseCalc account or cloud sync.
• Job contacts, worksheets, settings, and calculation history use the app's local storage.
• Subscription status is checked through RevenueCat; exports leave the app only when you choose to share them.
• No third-party advertising SDK or third-party ads in this release.
• Dark and light themes with a high-contrast job-site interface.
BaseCalc HVAC is a professional reference tool. Always verify against current industry standards, manufacturer data, and local codes. The authority having jurisdiction has the final say.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
Introducing Lifetime Pro: pay once to unlock every calculator and remove all ads for good. Existing monthly and yearly subscriptions remain valid and continue to renew as before.
The developer, BASEMAPPED LLC, 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:
- Purchases
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- BASEMAPPED LLC
- Size
- 55.8 MB
- Category
- Utilities
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - iPad
Requires iPadOS 16.4 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+
- Contains
Advertising
- In-App Purchases
Yes
- Lifetime Pro $14.99
- HVAC Pro Yearly $50.00
- HVAC Pro Monthly $7.00
- Copyright
- © 2026 BaseMapped LLC