BTUs per Square Foot to Langleys Converter
Enter the heat density in btus per square foot below to convert it to langleys.
Convert BTUs per Square Foot to Langleys
Enter a value in btus per square foot (BTU/ft²) to convert to langleys (Ly).
BTU per Square Foot to Langley Conversion Table
Table showing various btu per square foot measurements converted to langleys. Click any preset value or arrow to load it into the converter.
| BTUs per Square Foot (BTU/ft²) | Langleys (Ly) |
|---|---|
| 1 BTU/ft² | 0.2714275 Ly |
| 2 BTU/ft² | 0.542855 Ly |
| 2.5 BTU/ft² | 0.6785688 Ly |
| 5 BTU/ft² | 1.3571375 Ly |
| 10 BTU/ft² | 2.714275 Ly |
| 15 BTU/ft² | 4.0714125 Ly |
| 20 BTU/ft² | 5.42855 Ly |
| 25 BTU/ft² | 6.7856876 Ly |
| 30 BTU/ft² | 8.1428251 Ly |
| 50 BTU/ft² | 13.5713751 Ly |
How to Convert BTUs per Square Foot to Langleys
To convert btus per square foot to langleys, multiply the heat density by the following conversion ratio: 0.2714275 langleys/btu per square foot.
Since one btu per square foot is equal to 0.2714275 langleys, you can use this simple formula to convert:
The heat density in langleys is equal to the heat density in btus per square foot multiplied by 0.2714275.
For example, here's how to convert 5 btus per square foot to langleys using the formula above.
How Many Langleys Are in a BTU per Square Foot?
There are 0.2714275 langleys in a btu per square foot, which is why we use this value in the formula above.
Our btu per square foot to langley calculator automatically converts your heat density measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
BTUs per Square Foot and langleys are both units used to measure heat density. Keep reading to learn more about each unit.
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). [1]
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.
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). [2]
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.
When converting heat density between btus per square foot (BTU/ft²) and langleys (Ly), keep full floating-point precision (1 BTU/ft² = 0.2714275 Ly; 1 Ly = 3.684225 BTU/ft²) during intermediate calculations and round only the final langley figure to match your instrument tolerance.
More BTU per Square Foot & Langley Conversions
Need to calculate in the opposite direction? Use our langleys to btus per square foot calculator to switch your starting unit immediately. You can also explore related tools such as converting langleys to btus per square foot, converting joules per square meter to langleys, or converting joules per square meter to kilojoules per square meter.
Convert from BTUs per Square Foot
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Heat Density Metrology Standard — BTUs per Square Foot (BTU/ft²) to Langleys (Ly)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: BTU per Square Foot (BTU/ft²) & Langley (cal/cm²) (Ly)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (BTU/ft² to Ly)