Langleys to BTUs per Square Foot Converter
Enter the heat density in langleys below to convert it to btus per square foot.
Convert Langleys to BTUs per Square Foot
Enter a value in langleys (Ly) to convert to btus per square foot (BTU/ft²).
Langley to BTU per Square Foot Conversion Table
Table showing various langley measurements converted to btus per square foot. Click any preset value or arrow to load it into the converter.
| Langleys (Ly) | BTUs per Square Foot (BTU/ft²) |
|---|---|
| 1 Ly | 3.684225 BTU/ft² |
| 2 Ly | 7.3684501 BTU/ft² |
| 2.5 Ly | 9.2105626 BTU/ft² |
| 5 Ly | 18.4211252 BTU/ft² |
| 10 Ly | 36.8422504 BTU/ft² |
| 15 Ly | 55.2633756 BTU/ft² |
| 20 Ly | 73.6845007 BTU/ft² |
| 25 Ly | 92.1056259 BTU/ft² |
| 30 Ly | 110.5267511 BTU/ft² |
| 50 Ly | 184.2112518 BTU/ft² |
How to Convert Langleys to BTUs per Square Foot
To convert langleys to btus per square foot, multiply the heat density by the following conversion ratio: 3.684225 btus per square foot/langley.
Since one langley is equal to 3.684225 btus per square foot, you can use this simple formula to convert:
The heat density in btus per square foot is equal to the heat density in langleys multiplied by 3.684225.
For example, here's how to convert 5 langleys to btus per square foot using the formula above.
How Many BTUs per Square Foot Are in a Langley?
There are 3.684225 btus per square foot in a langley, which is why we use this value in the formula above.
Our langley to btu per square foot calculator automatically converts your heat density measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Langleys and btus per square foot are both units used to measure heat density. Keep reading to learn more about each unit.
What Is a Langley?
A langley is a unit of heat density equal to 41,840 joules per square meter (J/m²), the base unit for heat density. Solar insolation unit equal to 1 thermochemical calorie/cm² (41,840 J/m²). [1]
The langley is classified as a metric and SI-compatible unit of heat density. Langleys can be abbreviated as Ly; for example, 1 langley can be written as 1 Ly.
When working with langleys (Ly) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, langleys (Ly) are widely used across large-scale industrial, bulk, and macro-level heat density specifications within SI metric workflows, engineering documentation, and technical data sheets.
What Is a BTU per Square Foot?
A btu per square foot is a unit of heat density equal to 11,356.5267 joules per square meter (J/m²), the base unit for heat density. US thermal exposure unit (≈ 11,356.5 J/m²). [2]
The btu per square foot is classified as a US customary unit of heat density. BTUs per Square Foot can be abbreviated as BTU/ft²; for example, 1 btu per square foot can be written as 1 BTU/ft².
When working with btus per square foot (BTU/ft²) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, btus per square foot (BTU/ft²) are widely used across large-scale industrial, bulk, and macro-level heat density specifications within US customary workflows, engineering documentation, and technical data sheets.
When converting heat density between langleys (Ly) and btus per square foot (BTU/ft²), keep full floating-point precision (1 Ly = 3.684225 BTU/ft²; 1 BTU/ft² = 0.2714275 Ly) during intermediate calculations and round only the final btu per square foot figure to match your instrument tolerance.
More Langley & BTU per Square Foot Conversions
Need to calculate in the opposite direction? Use our btus per square foot to langleys calculator to switch your starting unit immediately. You can also explore related tools such as converting btus per square foot to langleys, converting langleys to joules per square meter, or converting joules per square meter to kilojoules per square meter.
Convert from Langleys
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Heat Density Metrology Standard — Langleys (Ly) to BTUs per Square Foot (BTU/ft²)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Langley (cal/cm²) (Ly) & BTU per Square Foot (BTU/ft²)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (Ly to BTU/ft²)