250+ iOS apps curated and reviewed
Out of 250+ btu calculator apps on iOS, 18 are free and the rest sit in the paid tier. This page sorts them so you can compare both sides before you commit.
| # | App | Price | Rating | Ads | In-App Purchases | Updated |
|---|---|---|---|---|---|---|
| 1 |  | Free | — | Yes | No | Jul 2026 |
| 2 |  | Free | 4.6★ (288) | Yes | Yes | Aug 2026 |
| 3 |  | Free | 5.0★ (5) | No | No | May 2026 |
| 4 |  | Free | 5.0★ (5) | Yes | Yes | May 2026 |
| 5 |  | Free | — | No | No | Jun 2026 |
| 6 |  | Free | 4.8★ (20) | No | Yes | May 2026 |
| 7 |  | Free | 4.0★ (8) | No | Yes | May 2026 |
| 8 |  | $0.99 | — | No | No | Jun 2026 |
Estimate the cooling capacity needed for your data center. This tool considers factors like space, occupants, and heat output to help you maintain optimal temperature and humidity. It provides instant results as you update inputs, serving as a guide for system selection.
This utility helps you determine the appropriate cooling capacity for an air conditioner based on room size and other factors. It simplifies the process of selecting the right unit to ensure optimal comfort and energy efficiency.
This tool helps you calculate the right size for air conditioners, heat pumps, and furnaces. It provides detailed analysis of heating and cooling costs, energy consumption, and temperature data. You can also evaluate domestic hot water needs and financial aspects like payback periods.
This utility app simplifies HVAC sizing by calculating BTU/h capacity and recommending equipment. It offers unit conversions, price estimates, and energy consumption comparisons. Advanced features can be unlocked via in-app purchases.
This tool provides HVAC technicians with instant access to pressure and temperature data for over 100 refrigerants. It allows users to input one value to find the other, view detailed refrigerant properties, and email comprehensive charts and data.
This advanced calculator app offers a powerful math core and algebra engine for basic to complex calculations. It includes features like step-by-step solutions, handwriting recognition, and 2D graphing, making it suitable for students, engineers, and programmers.
This app offers a comprehensive suite of over 40 calculators and unit converters for various needs, including finance, health, construction, and everyday math. It features standard, scientific, and specialized calculators for tasks like loan amortization, currency conversion, and material estimation.
This utility app offers a straightforward calculation experience with a vast selection of over 80 customizable themes. Personalize your calculator's appearance to suit your style while performing everyday math tasks.
This app is a versatile tool offering a wide range of calculation and conversion functions. It supports basic arithmetic, advanced math operations, unit conversions, and currency exchange. Designed for students, educators, and professionals, it provides an intuitive interface for daily calculations.
This application offers a high-precision calculation engine with a user-friendly interface. It allows for real-time result display as formulas are typed, supports multiple undo actions, and enables easy switching between workspaces. Users can also access persistent history, print calculations via AirPrint, and share history via email.
This app offers a suite of specialized calculators, including scientific, financial, programmer, and basic functions. It also features a currency converter and a comprehensive unit converter for various needs.
