Skip to main content

Foot-pounds/minute/sq. foot to Btus (th)/second/sq. foot Converter (ft·lbf/(min·ft²) to Btu/(s·ft²))

Rate this converter 0 of 0 ratings
Instant calculation with 0ms overhead
Popular Converters
Live Conversion • ISO 80000-5:2019 Certified
1 Foot-pound/minute/sq. foot = 2.14322202 × 10⁻⁵ BTU (th)/second/sq. foot
1 ft·lbf/(min·ft²) = 2.143222 × 10⁻⁵ Btu/(s·ft²) • 1 Btu/(s·ft²) = 46658.721731 ft·lbf/(min·ft²)
Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot: One Foot-pound/minute/sq. foot is equal to 2.14322202 × 10⁻⁵ Btus (th)/second/sq. foot.
Certified Authority Value
0.00002143
Btu/(s·ft²)
Exact: 1 Btu/(s·ft²) ≡ 46658.7217306006 ft·lbf/(min·ft²)
ft·lbf/(min·ft²)
ft·lbf/(min·ft²)
Btu/(s·ft²)
Btu/(s·ft²) 2.14322202 × 10⁻⁵
Quick Values:
Conversion Formula
To convert Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot, multiply by 2.14322202 × 10⁻⁵
ft·lbf/(min·ft²) × 2.14322202 × 10⁻⁵ = Btu/(s·ft²)

Calculation: 1 ft·lbf/(min·ft²) × 2.14322202 × 10⁻⁵ = 2.14322202 × 10⁻⁵ Btu/(s·ft²)

Common Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot Calculations

Quick-lookup reference table showing calculated equivalents for standard increments between Foot-pound/minute/sq. foot (ft·lbf/(min·ft²)) and BTU (th)/second/sq. foot (Btu/(s·ft²)).

Tap any row to calculate
Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot: Primary Direct Table (15 Steps)
Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot Conversion Reference Table
Conversion & Equivalent Value Scientific Notation
0.001 ft·lbf/(min·ft²) 2.143222 × 10⁻⁸ Btu/(s·ft²) 2.143 × 10⁻⁸
0.01 ft·lbf/(min·ft²) 2.143222 × 10⁻⁷ Btu/(s·ft²) 2.143 × 10⁻⁷
0.1 ft·lbf/(min·ft²) 2.143222 × 10⁻⁶ Btu/(s·ft²) 2.143 × 10⁻⁶
0.5 ft·lbf/(min·ft²) 1.071611 × 10⁻⁵ Btu/(s·ft²) 1.072 × 10⁻⁵
1 ft·lbf/(min·ft²) 2.143222 × 10⁻⁵ Btu/(s·ft²) 2.143 × 10⁻⁵
2 ft·lbf/(min·ft²) 4.286444 × 10⁻⁵ Btu/(s·ft²) 4.286 × 10⁻⁵
5 ft·lbf/(min·ft²) 0.000107161 Btu/(s·ft²) 1.072 × 10⁻⁴
10 ft·lbf/(min·ft²) 0.000214322 Btu/(s·ft²) 2.143 × 10⁻⁴
20 ft·lbf/(min·ft²) 0.000428644 Btu/(s·ft²) 4.286 × 10⁻⁴
25 ft·lbf/(min·ft²) 0.000535806 Btu/(s·ft²) 5.358 × 10⁻⁴
50 ft·lbf/(min·ft²) 0.00107161 Btu/(s·ft²) 1.072 × 10⁻³
100 ft·lbf/(min·ft²) 0.00214322 Btu/(s·ft²) 2.143 × 10⁻³
250 ft·lbf/(min·ft²) 0.00535806 Btu/(s·ft²) 5.358 × 10⁻³
500 ft·lbf/(min·ft²) 0.0107161 Btu/(s·ft²) 1.072 × 10⁻²
1000 ft·lbf/(min·ft²) 0.0214322 Btu/(s·ft²) 2.143 × 10⁻²
BTU (th)/second/sq. foot to Foot-pound/minute/sq. foot: Reciprocal Summary
BTU (th)/second/sq. foot to Foot-pound/minute/sq. foot Conversion Reference Table
Reciprocal & Equivalent Value Scientific Notation
1 Btu/(s·ft²) 46658.721731 ft·lbf/(min·ft²) 4.666 × 10⁴
5 Btu/(s·ft²) 233293.608653 ft·lbf/(min·ft²) 2.333 × 10⁵
10 Btu/(s·ft²) 466587.217306 ft·lbf/(min·ft²) 4.666 × 10⁵
50 Btu/(s·ft²) 2332936.08653 ft·lbf/(min·ft²) 2.333 × 10⁶
100 Btu/(s·ft²) 4665872.17306 ft·lbf/(min·ft²) 4.666 × 10⁶

Real-World Context & Everyday Benchmarks

Tap to load into converter

To help contextualize these units in everyday life, science, and engineering, here are verified real-world reference points for Foot-pound/minute/sq. foot (ft·lbf/(min·ft²)) and BTU (th)/second/sq. foot (Btu/(s·ft²)):

Foot-pound/minute/sq. foot References:

  • Solar constant extraterrestrial solar irradiance at top of atmosphere 5595.46 ft·lbf/(min·ft²)
  • Clear sky direct midday summer sunlight striking sea level ground 4111.29 ft·lbf/(min·ft²)
  • Human body resting thermal metabolic heat radiation to room 205.56 ft·lbf/(min·ft²)
  • Overcast winter day diffuse solar irradiance at sea level 411.13 ft·lbf/(min·ft²)

BTU (th)/second/sq. foot References:

  • Solar constant extraterrestrial solar irradiance at top of atmosphere 0.119923 Btu/(s·ft²)
  • Clear sky direct midday summer sunlight striking sea level ground 0.088114 Btu/(s·ft²)
  • Human body resting thermal metabolic heat radiation to room 0.004406 Btu/(s·ft²)
  • Overcast winter day diffuse solar irradiance at sea level 0.008811 Btu/(s·ft²)
ISQ Dimension: [M T⁻³] Coherent SI Unit: watt per square meter (W/m²) Thermodynamics & Heat Transfer

How to Convert Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot

Converting Foot-pound/minute/sq. foot (ft·lbf/(min·ft²)) to BTU (th)/second/sq. foot (Btu/(s·ft²)) is a core calculation in Heat Flux Density, which measures the rate of thermal energy transfer radiating or conducting through a unit area per second. This calculation navigates the boundary between the International Metric System (SI) and British Imperial / US Customary engineering standards. In contemporary metrology, Imperial units are defined in terms of exact SI standards via international agreements—notably NIST SP 811 and the 1959 International Yard and Pound Agreement. Exactly 1 Foot-pound/minute/sq. foot equals 2.143222 × 10⁻⁵ BTU (th)/second/sq. foot, while 1 Btu/(s·ft²) equals 46658.721731 ft·lbf/(min·ft²).

Direct Factor1 ft·lbf/(min·ft²) = 2.143222 × 10⁻⁵ Btu/(s·ft²)
Inverse Ratio1 Btu/(s·ft²) = 46658.721731 ft·lbf/(min·ft²)
Conversion ScaleMetric SI to British Imperial / US Customary Bridge
First-Principles SI Derivation ProofNIST SP 811 / ISO 80000 Compliance

Mathematical Conversion Derivation via Coherent SI Base Unit

Under the International System of Quantities (ISQ), dimensional conversion between non-SI units is rigorously resolved by bridging through the coherent SI base unit (watt per square meter (W/m²)) without arbitrary rounding:

Vtarget=Vsource×(ksource→SIktarget→SI)V_{\text{target}} = V_{\text{source}} \times \left( \frac{k_{\text{source} \to \text{SI}}}{k_{\text{target} \to \text{SI}}} \right)
Universal Dimensional Conversion Law (ISO 80000 / NIST SP 811)
1. Source SI Bridge (ksource):1 ft·lbf/(min·ft²) = 0.243233 watt per square meter (W/m²)
2. Target SI Bridge (ktarget):1 Btu/(s·ft²) = 11348.93 watt per square meter (W/m²)
Step-by-step substitution for Foot-pound/minute/sq. foot → BTU (th)/second/sq. foot:V(Btu/(s·ft²)) = V(ft·lbf/(min·ft²)) × ( 0.243233 / 11348.93 ) = V(ft·lbf/(min·ft²)) × 2.143222 × 10⁻⁵
Mathematical FormulaValue in BTU (th)/second/sq. foot = Value in Foot-pound/minute/sq. foot × 2.14322202 × 10⁻⁵Direct computational formula applied for standard conversion.
Worked Example

For an engineering input of 36 ft·lbf/(min·ft²), applying the conversion factor yields exactly 0.00077156 Btu/(s·ft²). At larger operational scale, 1000 Foot-pound/minute/sq. foot corresponds to 0.0214322 Btu/(s·ft²).

Inverse check: 1 Btu/(s·ft²) = 46658.721731 ft·lbf/(min·ft²).

Understanding Foot-pound/minute/sq. foot and BTU (th)/second/sq. foot

Foot-pound/minute/sq. foot

ft·lbf/(min·ft²)
Imperial / US

A Foot-pound/minute/sq. foot (ft·lbf/(min·ft²)) is an imperial and US customary unit for heat flux density.

Applications & Practical Context

In practical heat flux density terms, a solar constant extraterrestrial solar irradiance at top of atmosphere equals 5595.46 ft·lbf/(min·ft²), a clear sky direct midday summer sunlight striking sea level ground equals 4111.29 ft·lbf/(min·ft²), a human body resting thermal metabolic heat radiation to room equals 205.56 ft·lbf/(min·ft²).

Physical Setup

A physical magnitude of 1 ft·lbf/(min·ft²) corresponds to 0.243233 W/m² in standard SI measurement.

Conversion to SI Unit: watt per square meter (W/m²)
1 ft·lbf/(min·ft²) = 0.243233 W/m²

BTU (th)/second/sq. foot

Btu/(s·ft²)
Imperial / US

A BTU (th)/second/sq. foot (Btu/(s·ft²)) is an imperial and US customary unit for heat flux density.

Applications & Practical Context

In practical heat flux density terms, a solar constant extraterrestrial solar irradiance at top of atmosphere equals 0.119923 Btu/(s·ft²), a clear sky direct midday summer sunlight striking sea level ground equals 0.088114 Btu/(s·ft²), a human body resting thermal metabolic heat radiation to room equals 0.004406 Btu/(s·ft²).

Physical Setup

A physical magnitude of 1 Btu/(s·ft²) corresponds to 11348.93 W/m² in standard SI measurement.

Conversion to SI Unit: watt per square meter (W/m²)
1 Btu/(s·ft²) = 11348.93 W/m²

Domain Metrology & Engineering Applications

Governing Law & Equation

Thermal Transmission Flux (q = Q̇ / A)

Measurement Instrumentation

Rigorously quantified in laboratory and field settings using Schmidt-Boelter heat flux gauges, differential thermopile foil transducers, and calibrated Gardon radiant gauges.

Primary Industry Sectors

Applied across rocket nozzle combustion chamber analysis, fire resistance testing (ASTM E119), furnace wall heat loss auditing, and hypersonic aerothermal design under international metrology standard ISO 80000-5:2019, ASME PTC 19.3.

Institutional Metrology & Standard Authority:

Formulas, conversion coefficients, and base definitions on this page strictly adhere to the ISO 80000-5:2019, ASME PTC 19.3 and the BIPM SI Brochure (9th Edition). Governed by Thermal Transmission Flux (q = Q̇ / A) under ISO 80000 dimensional vector [M T⁻³].

Multi-Variable Engineering Bridge Thermal Radiation & Power Dissipation

Heat Flux Density to Total Thermal Power Bridge (Watts • Kilowatts • Megawatts • BTU/h • Horsepower)

Calculate total continuous heat dissipation power P = q" × A across surface barriers and exchangers, bridging heat flux density [M T⁻³] with thermal power [M L² T⁻³].

P = q" × A
Vector: [W/m²] × [m²] → [W]
Live Calculated Bridge Equivalent:
1 ft·lbf/(min·ft²) at Industrial Hydronic Radiator Panel (8 m²) = 1.9459 W
Equals 0.001946 kW • 1.945862 × 10⁻⁶ MW • 0.002609 hp
SI Power
1.9459
W
Watts
Grid / Utility
0.001946
kW
Kilowatts
Power Plant
1.945862 × 10⁻⁶
MW
Megawatts
Mechanical Rating
0.002609
hp
Horsepower (Mechanical)
Metric Horsepower
0.002646
PS
Metric Horsepower (PS)
HVAC Thermal Rating
6.64
BTU/h
BTU per Hour
  1. 1. Normalize Input to SI Base Unit (W/m²):
    q" = 1 ft·lbf/(min·ft²) × 0.24323277 = 0.24323277 W/m²
  2. 2. Apply Engineering Parameter (A):
    Selected condition: Industrial Hydronic Radiator Panel (8 m²) at A = 8 m²
  3. 3. Execute Governing Physical Law in SI Units:
    P = q" × A = (0.24323277 W/m²) × (8 m²) = 1.945862 W
  4. 4. Convert to Standard Engineering Units:
    • W: 1.945862 × 1 = 1.9459 W (Watts) • kW: 1.945862 × 0.001 = 0.001946 kW (Kilowatts) • MW: 1.945862 × 1 × 10⁻⁶ = 1.945862 × 10⁻⁶ MW (Megawatts) • hp: 1.945862 × 0.001341 = 0.002609 hp (Horsepower (Mechanical)) • PS: 1.945862 × 0.00136 = 0.002646 PS (Metric Horsepower (PS)) • BTU/h: 1.945862 × 3.4121 = 6.64 BTU/h (BTU per Hour)
Explore Full Power Converter →
Engineering Substance / Operating Standard Parameter Value (m²) Reference State / Condition Typical Industrial & Engineering Application
Residential Window Glazing (4 m²) 4 4.0 m² Double-pane exterior window glass aperture
Industrial Hydronic Radiator Panel (8 m²) 8 8.0 m² Convective space heating radiator surface
Shell & Tube Heat Exchanger (50 m²) 50 50.0 m² Industrial process fluid cooling bundle
Power Boiler Waterwall (200 m²) 200 200.0 m² Thermal power plant steam generator wall
Embed
Need this Foot-pound/minute/sq. foot to BTU (th)/second/sq. foot calculator on your website, lab portal, or research blog?
Free HTML Widget 100% Responsive Zero Cookie Tracking
Notice a calculation discrepancy, rounding error, or glitch?
Help us maintain 100% scientific precision and report any issues directly to engineering.

Frequently Asked Questions

There are exactly 2.14322202 × 10⁻⁵ btus (th)/second/sq. foot (Btu/(s·ft²)) in 1 foot-pound/minute/sq. foot (ft·lbf/(min·ft²)). To calculate larger amounts manually, simply multiply your total number of foot-pounds/minute/sq. foot by the conversion multiplier of 2.14322202 × 10⁻⁵.

The mathematical formula to convert foot-pounds/minute/sq. foot to btus (th)/second/sq. foot is: [value] * 2.14322202 × 10⁻⁵ = btus (th)/second/sq. foot. Rather than doing the math manually, you can use our high-precision online calculator to process this exact equation instantly without rounding errors.

To perform the reverse calculation from btus (th)/second/sq. foot back to foot-pounds/minute/sq. foot, you must divide your starting value by 2.14322202 × 10⁻⁵. Our bidirectional tool automatically computes this inverse equation the moment you type into the btu (th)/second/sq. foot input field.

1 BTU (th)/second/sq. foot is larger than 1 Foot-pound/minute/sq. foot. Specifically, 1 Foot-pound/minute/sq. foot equals 2.14322202 × 10⁻⁵ btus (th)/second/sq. foot, meaning 1 BTU (th)/second/sq. foot is 46658.7217 times larger than 1 Foot-pound/minute/sq. foot (a difference of 4.67 orders of magnitude). Expressing measurements in foot-pounds/minute/sq. foot requires a larger numerical value to represent the equivalent physical magnitude.

Under standard international measurement guidelines, 1 Foot-pound/minute/sq. foot converts to 2.14322202 × 10⁻⁵ btus (th)/second/sq. foot. Precise numerical conversion factors ensure consistency across laboratory, engineering, and field data.