BTU Calculator - AC, Heat Pump

NRG Labs

About this app

This application is a must for any plumber, builder or home DIY enthusiast, in fact anyone who wants to find out what radiator or AC BTU's are required for a particular room size.


Whether you have existing radiators (or Fan Coil Units - FCU) and want to check that they are the correct size or if you are adding a new radiator (FCU) to a room - this is the application for you.


⭐⭐⭐ BTU Calculator Features ⭐⭐⭐

✓ Basic Calculations

✓ Advanced Calculations

✓ Electricity consumption and cost (monthly and annual) for your system

✓ Location based climate data

✓ AC or Heating Calculations for temperature increase/ decrease

✓ Room volume

✓ Room use

✓ Double glazing plastic/ metal/ wooden frame windows

✓ Single glazing metal/ wooden frame windows

✓ Insulated/ uninsulated walls

✓ Room position


The annual simulation of the required system will give you a detailed electricity consumption and cost during winter months.


Choose the right size of heat pump, AC or any other thermal source.


Do not undersize or oversize your system. Make an informed decision and choose the correct design/ power.


Design your new home or check your existing one, and be prepared before you receive any offer from the companies or plumbers.


The simple yet intuitive interface allows you the choice of measurements in feet or meters, Celsius or Fahrenheit degrees.


This calculator has the added benefit of showing you the BTU required and also the kW required.


Thank you for using our app!

Ratings and reviews

1 of the best BTU calculators out here . Simple to use some realy upto date features . I personaly could do with more features like doors with windows glass sizes and selection of each wall in a room to be of a different type . And some heat gains from length of visable pipes etc .it could also do with ability of switching between t65 t50 and t30 btu ratings.

Wowza this is bad. I was expecting WAY more for a paid app. Seriously.... You only offer brick walls and barely any other options even under advanced BTU calc. No air intrusion amounts or anything. I get better calcs for free. Uninstalling and getting refund asap

While I appreciate the function of this app for a low price, it lacks many building material options. It has a lot of potential but it needs expansion so that it includes more wall assembly material options.

What’s new

✓ New Interface with a lot of additional functionalities
✓ PDF Export, CSV Export
✓ Heating and Cooling Systems: Heat Pumps, AC, Electric Heaters, Oil Furnace, Gas Furnace, Wood Furnace
✓ Performance improvements
✓ Bug fixes

Thank you!
PV Solcast Team
pvsolcast.com