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Btus (th)/second/sq. foot to Calories (it)/second/cm² Converter (Btu/(s·ft²) to cal/(s·cm²))

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Live Conversion • ISO 80000-5:2019 Certified
1 BTU (th)/second/sq. foot = 0.27106454 Calorie (IT)/second/cm²
1 Btu/(s·ft²) = 0.271065 cal/(s·cm²) • 1 cal/(s·cm²) = 3.689158 Btu/(s·ft²)
BTU (th)/second/sq. foot to Calorie (IT)/second/cm²: One BTU (th)/second/sq. foot is equal to 0.27106454 Calories (it)/second/cm².
Certified Authority Value
0.27106454
cal/(s·cm²)
Exact: 1 cal/(s·cm²) ≡ 3.6891583612 Btu/(s·ft²)
Btu/(s·ft²)
Btu/(s·ft²)
cal/(s·cm²)
cal/(s·cm²) 0.27106454
Quick Values:
Conversion Formula
To convert BTU (th)/second/sq. foot to Calorie (IT)/second/cm², multiply by 0.27106454
Btu/(s·ft²) × 0.27106454 = cal/(s·cm²)

Calculation: 1 Btu/(s·ft²) × 0.27106454 = 0.27106454 cal/(s·cm²)

Common BTU (th)/second/sq. foot to Calorie (IT)/second/cm² Calculations

Quick-lookup reference table showing calculated equivalents for standard increments between BTU (th)/second/sq. foot (Btu/(s·ft²)) and Calorie (IT)/second/cm² (cal/(s·cm²)).

Tap any row to calculate
BTU (th)/second/sq. foot to Calorie (IT)/second/cm²: Primary Direct Table (15 Steps)
BTU (th)/second/sq. foot to Calorie (IT)/second/cm² Conversion Reference Table
Conversion & Equivalent Value Scientific Notation
0.001 Btu/(s·ft²) 0.000271065 cal/(s·cm²) 2.711 × 10⁻⁴
0.01 Btu/(s·ft²) 0.00271065 cal/(s·cm²) 2.711 × 10⁻³
0.1 Btu/(s·ft²) 0.0271065 cal/(s·cm²) 2.711 × 10⁻²
0.5 Btu/(s·ft²) 0.135532 cal/(s·cm²) 1.355 × 10⁻¹
1 Btu/(s·ft²) 0.271065 cal/(s·cm²) 2.711 × 10⁻¹
2 Btu/(s·ft²) 0.542129 cal/(s·cm²) 5.421 × 10⁻¹
5 Btu/(s·ft²) 1.355323 cal/(s·cm²) 1.355 × 10⁰
10 Btu/(s·ft²) 2.710645 cal/(s·cm²) 2.711 × 10⁰
20 Btu/(s·ft²) 5.421291 cal/(s·cm²) 5.421 × 10⁰
25 Btu/(s·ft²) 6.776613 cal/(s·cm²) 6.777 × 10⁰
50 Btu/(s·ft²) 13.553227 cal/(s·cm²) 1.355 × 10¹
100 Btu/(s·ft²) 27.106454 cal/(s·cm²) 2.711 × 10¹
250 Btu/(s·ft²) 67.766134 cal/(s·cm²) 6.777 × 10¹
500 Btu/(s·ft²) 135.532268 cal/(s·cm²) 1.355 × 10²
1000 Btu/(s·ft²) 271.064536 cal/(s·cm²) 2.711 × 10²
Calorie (IT)/second/cm² to BTU (th)/second/sq. foot: Reciprocal Summary
Calorie (IT)/second/cm² to BTU (th)/second/sq. foot Conversion Reference Table
Reciprocal & Equivalent Value Scientific Notation
1 cal/(s·cm²) 3.689158 Btu/(s·ft²) 3.689 × 10⁰
5 cal/(s·cm²) 18.445792 Btu/(s·ft²) 1.845 × 10¹
10 cal/(s·cm²) 36.891584 Btu/(s·ft²) 3.689 × 10¹
50 cal/(s·cm²) 184.457918 Btu/(s·ft²) 1.845 × 10²
100 cal/(s·cm²) 368.915836 Btu/(s·ft²) 3.689 × 10²

Real-World Context & Everyday Benchmarks

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To help contextualize these units in everyday life, science, and engineering, here are verified real-world reference points for BTU (th)/second/sq. foot (Btu/(s·ft²)) and Calorie (IT)/second/cm² (cal/(s·cm²)):

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)

Calorie (IT)/second/cm² References:

  • Solar constant extraterrestrial solar irradiance at top of atmosphere 0.032507 cal/(s·cm²)
  • Clear sky direct midday summer sunlight striking sea level ground 0.023885 cal/(s·cm²)
  • Human body resting thermal metabolic heat radiation to room 0.001194 cal/(s·cm²)
  • Overcast winter day diffuse solar irradiance at sea level 0.002388 cal/(s·cm²)
ISQ Dimension: [M T⁻³] Coherent SI Unit: watt per square meter (W/m²) Thermodynamics & Heat Transfer

How to Convert BTU (th)/second/sq. foot to Calorie (IT)/second/cm²

Converting BTU (th)/second/sq. foot (Btu/(s·ft²)) to Calorie (IT)/second/cm² (cal/(s·cm²)) 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 BTU (th)/second/sq. foot equals 0.271065 Calorie (IT)/second/cm², while 1 cal/(s·cm²) equals 3.689158 Btu/(s·ft²).

Direct Factor1 Btu/(s·ft²) = 0.271065 cal/(s·cm²)
Inverse Ratio1 cal/(s·cm²) = 3.689158 Btu/(s·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 Btu/(s·ft²) = 11348.93 watt per square meter (W/m²)
2. Target SI Bridge (ktarget):1 cal/(s·cm²) = 41868 watt per square meter (W/m²)
Step-by-step substitution for BTU (th)/second/sq. foot → Calorie (IT)/second/cm²:V(cal/(s·cm²)) = V(Btu/(s·ft²)) × ( 11348.93 / 41868 ) = V(Btu/(s·ft²)) × 0.271065
Mathematical FormulaValue in Calorie (IT)/second/cm² = Value in BTU (th)/second/sq. foot × 0.27106454Direct computational formula applied for standard conversion.
Worked Example

Converting 15 Btu/(s·ft²) yields an exact output of 4.065968 cal/(s·cm²) in Calorie (IT)/second/cm². Under higher industrial throughput, 5000 Btu/(s·ft²) translates to 1355.322681 cal/(s·cm²).

Inverse check: 1 cal/(s·cm²) = 3.689158 Btu/(s·ft²).

Understanding BTU (th)/second/sq. foot and Calorie (IT)/second/cm²

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

Calorie (IT)/second/cm²

cal/(s·cm²)
Standard Unit

A Calorie (IT)/second/cm² (cal/(s·cm²)) is a recognized 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 0.032507 cal/(s·cm²), a clear sky direct midday summer sunlight striking sea level ground equals 0.023885 cal/(s·cm²), a human body resting thermal metabolic heat radiation to room equals 0.001194 cal/(s·cm²).

Physical Setup

A physical magnitude of 1 cal/(s·cm²) corresponds to 41868 W/m² in standard SI measurement.

Conversion to SI Unit: watt per square meter (W/m²)
1 cal/(s·cm²) = 41868 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 Btu/(s·ft²) at Industrial Hydronic Radiator Panel (8 m²) = 90791.44 W
Equals 90.7914 kW • 0.0907914 MW • 121.7533 hp
SI Power
90791.44
W
Watts
Grid / Utility
90.7914
kW
Kilowatts
Power Plant
0.0907914
MW
Megawatts
Mechanical Rating
121.7533
hp
Horsepower (Mechanical)
Metric Horsepower
123.442
PS
Metric Horsepower (PS)
HVAC Thermal Rating
309793.25
BTU/h
BTU per Hour
  1. 1. Normalize Input to SI Base Unit (W/m²):
    q" = 1 Btu/(s·ft²) × 11348.93 = 11348.93 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 = (11348.93 W/m²) × (8 m²) = 90791.44 W
  4. 4. Convert to Standard Engineering Units:
    • W: 90791.44 × 1 = 90791.44 W (Watts) • kW: 90791.44 × 0.001 = 90.7914 kW (Kilowatts) • MW: 90791.44 × 1 × 10⁻⁶ = 0.0907914 MW (Megawatts) • hp: 90791.44 × 0.001341 = 121.7533 hp (Horsepower (Mechanical)) • PS: 90791.44 × 0.00136 = 123.442 PS (Metric Horsepower (PS)) • BTU/h: 90791.44 × 3.4121 = 309793.25 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
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Frequently Asked Questions

There are exactly 0.27106454 calories (it)/second/cm² (cal/(s·cm²)) in 1 btu (th)/second/sq. foot (Btu/(s·ft²)). To calculate larger amounts manually, simply multiply your total number of btus (th)/second/sq. foot by the conversion multiplier of 0.27106454.

The mathematical formula to convert btus (th)/second/sq. foot to calories (it)/second/cm² is: [value] * 0.27106454 = calories (it)/second/cm². 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 calories (it)/second/cm² back to btus (th)/second/sq. foot, you must divide your starting value by 0.27106454. Our bidirectional tool automatically computes this inverse equation the moment you type into the calorie (it)/second/cm² input field.

1 Calorie (IT)/second/cm² is larger than 1 BTU (th)/second/sq. foot. Specifically, 1 BTU (th)/second/sq. foot equals 0.27106454 calories (it)/second/cm², meaning 1 Calorie (IT)/second/cm² is 3.6892 times larger than 1 BTU (th)/second/sq. foot (a difference of 0.57 orders of magnitude). Expressing measurements in btus (th)/second/sq. foot requires a larger numerical value to represent the equivalent physical magnitude.

Under standard international measurement guidelines, 1 BTU (th)/second/sq. foot converts to 0.27106454 calories (it)/second/cm². Precise numerical conversion factors ensure consistency across laboratory, engineering, and field data.