# BTU Calculator

> Estimate BTU requirement for heating or cooling a room.

Page: https://askcalculators.com/calculator/btu-calculator/
Definition: https://askcalculators.com/calculator/btu-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/btu-calculator/schema.json
Version: 7.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/btu-calculator/?length=20&width=15&ceilingHeight=8&insulation=average&sunExposure=average

## Inputs
- length: Length (ft); type=number; optional; default=20
- width: Width (ft); type=number; optional; default=15
- ceilingHeight: Ceiling Height (ft); type=number; optional; default=8
- insulation: Insulation; type=text; optional; default=average
- sunExposure: Sun Exposure; type=text; optional; default=average

## Outputs
- result: Result; format=text; primary

## Formula
Heating/cooling capacity is estimated from room volume, temperature difference, insulation factor, occupancy, and selected adjustments.

General sizing estimate. Equipment selection should account for local climate, construction, ventilation, and a professional load calculation.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: General sizing estimate. Equipment selection should account for local climate, construction, ventilation, and a professional load calculation.