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Radiator / BTU Calculator

Radiator / BTU Calculator

Size your radiator for heat

1 ratings
34 reviews
🔧 Utilities
📊 Productivity

Archived App (Last seen on 19 Nov 2025)

This is an archived listing of the app previously available on the App Store.

Although the app is no longer distributed by Apple, you can still view its description, screenshots, version history, ratings, and metadata for reference.

Details

Released
October 19, 2010
Updated
September 15, 2019

Features

Developer

Claire Holmes
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iphone
ipad
⭐34
Reviews↘︎
🔄6+ apps
Alternatives↘︎
❓5 answered
FAQ↘︎
📦w/o updates
Updates frequency↘︎
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About

Calculate the required BTU and kW for any room to properly size radiators. This tool is ideal for plumbers, builders, and DIYers, offering options for various room characteristics and measurement units. Save your calculations for future reference.

✓Calculate BTU and kW requirements
✓Adjust for room volume and use
✓Account for glazing and wall types
✓Support for feet or meter measurements
✓Save and store results
✓Includes unit converters
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What's New in Radiator / BTU Calculator

7.0.0

September 15, 2019

Completely redesigned interface for all screen sizes. Added handy gross / net BTU/KW conversion tool. Added handy Celsius to Fahrenheit conversion tool. NOTE - Please backup or take a note of your saved results before updating.

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User reviews

Most RecentHighest RatedLowest Rated

Help

Just Purchased App and it will not open?
HHowardw5000

Doesn’t Work

I have just paid £1.99 for this and it doesn’t open, please fix
HTHoward Trevor

Good app but won’t open anymore.

Good app but it is no longer opening on iPhone 13pro iOS 16.3.1. Please provide solution
**AndyC*

Don’t spend your money

Should have read the reviews first - just bought it and it doesn’t load.

Shame looked like a good - just what I was looking for
SSimon4205

Does not work

Paid to use this app does not work all you get is a picture of a dog
Nnigizy
See 29 more reviews

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FAQ

What does the Radiator / BTU Calculator app do?

This application helps users calculate the necessary BTU (British Thermal Units) and kW (kilowatts) required for a specific room to properly size radiators. It's designed for plumbers, builders, and DIY enthusiasts who need to ensure adequate heating for a space.

What factors can I adjust for the BTU calculation?

You can adjust for various factors including room volume, room use, presence of double glazing, whether the room is north-facing, French windows, flooring type, wall insulation (foam-filled or uninsulated cavity walls), and the number of outside walls (2 or 3). You can also choose your preferred units of measurement.

Is this app free to use?

Yes, the application is available for free. There are no in-app purchases or advertisements mentioned, indicating a completely free user experience.

Can I save my calculations?

Yes, the app allows you to save your calculated BTU and kW requirements directly within the application's database. This feature helps you keep track of your heating calculations without needing to write them down on scraps of paper.

What other tools are included in the app?

In addition to the main BTU calculator, the app includes a free Celsius to Fahrenheit converter and a gross/net kW/BTU converter. These tools provide further utility for heating-related calculations and conversions.