Convert Watts per Square Meter to BTU per Hour-Square Foot
Instantly convert Watts per Square Meter (W/m²) to BTU per Hour-Square Foot (BTU/(hr·ft²)) with our free online calculator.
Formula: W/m² to BTU/(hr·ft²) — multiply by 0.316998
Reference Table
| Watts per Square Meter (W/m²) | BTU per Hour-Square Foot (BTU/(hr·ft²)) |
|---|---|
| 1 | 0.316998 |
| 5 | 1.58499 |
| 10 | 3.16998 |
| 25 | 7.92496 |
| 50 | 15.8499 |
| 100 | 31.6998 |
How to Convert Watts per Square Meter to BTU per Hour-Square Foot
Formula
To convert Watts per Square Meter (W/m²) to BTU per Hour-Square Foot (BTU/(hr·ft²)): multiply by 0.316998
Step-by-Step
- Start with your value in Watts per Square Meter (W/m²).
- Multiply by 0.316998 to perform the conversion.
- The result is your value expressed in BTU per Hour-Square Foot (BTU/(hr·ft²)).
Conversion Factor
1 W/m² = 0.316998 BTU/(hr·ft²)
Reverse Factor
1 BTU/(hr·ft²) = 3.15459 W/m²
Worked Example
Convert 25 Watts per Square Meter to BTU per Hour-Square Foot: 25 W/m² = 7.92496 BTU/(hr·ft²)
About Watt per Square Meter (W/m²)
The SI unit of heat flux density — rate of heat flow per unit area. W/m² is the universal unit in heat-transfer analysis, solar-irradiance measurements (solar constant ≈ 1,361 W/m² at Earth's top of atmosphere; ~1,000 W/m² at sea level on a clear day), building-envelope thermal modeling, and electronics cooling. Also the SI unit for radiation intensity.
About BTU per Hour-Square Foot (BTU/(hr·ft²))
An imperial heat-flux unit used in US HVAC, building-envelope analysis, and heat-exchanger design. ASHRAE design loads, solar heat-gain tables for windows, and HVAC equipment ratings commonly use BTU/(hr·ft²). Common peak solar heat gain through a south-facing window might be 200–300 BTU/(hr·ft²). 1 BTU/(hr·ft²) ≈ 3.155 W/m².
Quick Facts
- 1 Watt per Square Meter equals 0.316998 BTU per Hour-Square Foot
- 1 BTU per Hour-Square Foot equals 3.15459 Watts per Square Meter
- Watt per Square Meter is a unit of heat flux
- BTU per Hour-Square Foot is a unit of heat flux
- This conversion is commonly used in fire protection engineering, electronics cooling, and solar energy
- The Watt per Square Meter belongs to the metric system
- The BTU per Hour-Square Foot belongs to the imperial system
Common Watt per Square Meter to BTU per Hour-Square Foot Conversions
| Watts per Square Meter (W/m²) | BTU per Hour-Square Foot (BTU/(hr·ft²)) |
|---|---|
| 0.01 | 0.00316998 |
| 0.1 | 0.0316998 |
| 0.25 | 0.0792496 |
| 0.5 | 0.158499 |
| 1 | 0.316998 |
| 2 | 0.633997 |
| 3 | 0.950995 |
| 5 | 1.58499 |
| 10 | 3.16998 |
| 15 | 4.75498 |
| 20 | 6.33997 |
| 25 | 7.92496 |
| 50 | 15.8499 |
| 75 | 23.7749 |
| 100 | 31.6998 |
| 250 | 79.2496 |
| 500 | 158.499 |
| 1000 | 316.998 |
| 5000 | 1584.99 |
| 10000 | 3169.98 |
Understanding Watts per Square Meter
The Watt per Square Meter (symbol: W/m²) is a unit of heat flux. The SI unit of heat flux density — rate of heat flow per unit area. W/m² is the universal unit in heat-transfer analysis, solar-irradiance measurements (solar constant ≈ 1,361 W/m² at Earth's top of atmosphere; ~1,000 W/m² at sea level on a clear day), building-envelope thermal modeling, and electronics cooling. Also the SI unit for radiation intensity.
It belongs to the metric measurement system.
Watts per Square Meter are commonly used in fire protection engineering, electronics cooling, and solar energy.
Understanding BTU per Hour-Square Foot
The BTU per Hour-Square Foot (symbol: BTU/(hr·ft²)) is a unit of heat flux. An imperial heat-flux unit used in US HVAC, building-envelope analysis, and heat-exchanger design. ASHRAE design loads, solar heat-gain tables for windows, and HVAC equipment ratings commonly use BTU/(hr·ft²). Common peak solar heat gain through a south-facing window might be 200–300 BTU/(hr·ft²). 1 BTU/(hr·ft²) ≈ 3.155 W/m².
It belongs to the imperial measurement system.
BTU per Hour-Square Foot are commonly used in fire protection engineering, electronics cooling, and solar energy.
Why Convert Watts per Square Meter to BTU per Hour-Square Foot?
Converting between Watts per Square Meter and BTU per Hour-Square Foot is a frequent requirement for engineers, scientists, and students working with heat flux values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate heat flux conversion is essential.
Frequently Asked Questions
How do I convert Watts per Square Meter to BTU per Hour-Square Foot?
The SI unit of heat flux density — rate of heat flow per unit area. To convert Watts per Square Meter to BTU per Hour-Square Foot, multiply by 0.316998. For example, 25 W/m² equals 7.92496 BTU/(hr·ft²).
How many BTU per Hour-Square Foot are in 1 Watt per Square Meter?
There are 0.316998 BTU per Hour-Square Foot in 1 Watt per Square Meter.
How many Watts per Square Meter are in 1 BTU per Hour-Square Foot?
There are 3.15459 Watts per Square Meter in 1 BTU per Hour-Square Foot.
What is the formula for Watt per Square Meter to BTU per Hour-Square Foot conversion?
The formula is: multiply by 0.316998. This means 1 W/m² = 0.316998 BTU/(hr·ft²).
Is a Watt per Square Meter bigger than a BTU per Hour-Square Foot?
Yes. One Watt per Square Meter is larger than one BTU per Hour-Square Foot because 1 W/m² equals 0.316998 BTU/(hr·ft²), which is less than 1.
When do you need to convert between Watts per Square Meter and BTU per Hour-Square Foot?
An imperial heat-flux unit used in US HVAC, building-envelope analysis, and heat-exchanger design. Watt per Square Meter and BTU per Hour-Square Foot are both heat flux units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.