Skip to main content
0 results ↑ ↓ navigate, ↵ select

Lumens/sq. foot/steradian to Candelas/square inch Converter (lm/(ft²·sr) to cd/in²)

Rate this converter 0 of 0 ratings
Instant calculation with 0ms overhead
Popular Converters
Live Conversion • ISO 80000-7:2019 Certified
1 Lumen/sq. foot/steradian = 0.0069444442 Candela/square inch
1 lm/(ft²·sr) = 0.00694444 cd/in² • 1 cd/in² = 144.000006 lm/(ft²·sr)
Lumen/sq. foot/steradian to Candela/square inch: One Lumen/sq. foot/steradian is equal to 0.0069444442 Candelas/square inch.
Certified Authority Value
0.00694444
cd/in²
Exact: 1 cd/in² ≡ 144.0000055742 lm/(ft²·sr)
lm/(ft²·sr)
lm/(ft²·sr)
Swap to Candela/square inch to Lumen/sq. foot/steradian
Swap to Candela/square inch to Lumen/sq. foot/steradian
cd/in²
cd/in² 0.0069444442
Quick Values:
Conversion Formula
To convert Lumen/sq. foot/steradian to Candela/square inch, multiply by 0.0069444442
lm/(ft²·sr) × 0.0069444442 = cd/in²

Calculation: 1 lm/(ft²·sr) × 0.0069444442 = 0.0069444442 cd/in²

Common Lumen/sq. foot/steradian to Candela/square inch Calculations

Quick-lookup reference table showing calculated equivalents for standard increments between Lumen/sq. foot/steradian (lm/(ft²·sr)) and Candela/square inch (cd/in²).

Tap any row to calculate
Lumen/sq. foot/steradian to Candela/square inch: Primary Direct Table (15 Steps)
Lumen/sq. foot/steradian to Candela/square inch Conversion Reference Table
Conversion & Equivalent Value Scientific Notation
0.001 lm/(ft²·sr) 6.944444 × 10⁻⁶ cd/in² 6.944 × 10⁻⁶
0.01 lm/(ft²·sr) 6.944444 × 10⁻⁵ cd/in² 6.944 × 10⁻⁵
0.1 lm/(ft²·sr) 0.000694444 cd/in² 6.944 × 10⁻⁴
0.5 lm/(ft²·sr) 0.00347222 cd/in² 3.472 × 10⁻³
1 lm/(ft²·sr) 0.00694444 cd/in² 6.944 × 10⁻³
2 lm/(ft²·sr) 0.0138889 cd/in² 1.389 × 10⁻²
5 lm/(ft²·sr) 0.0347222 cd/in² 3.472 × 10⁻²
10 lm/(ft²·sr) 0.0694444 cd/in² 6.944 × 10⁻²
20 lm/(ft²·sr) 0.138889 cd/in² 1.389 × 10⁻¹
25 lm/(ft²·sr) 0.173611 cd/in² 1.736 × 10⁻¹
50 lm/(ft²·sr) 0.347222 cd/in² 3.472 × 10⁻¹
100 lm/(ft²·sr) 0.694444 cd/in² 6.944 × 10⁻¹
250 lm/(ft²·sr) 1.736111 cd/in² 1.736 × 10⁰
500 lm/(ft²·sr) 3.472222 cd/in² 3.472 × 10⁰
1000 lm/(ft²·sr) 6.944444 cd/in² 6.944 × 10⁰
Candela/square inch to Lumen/sq. foot/steradian: Reciprocal Summary
Candela/square inch to Lumen/sq. foot/steradian Conversion Reference Table
Reciprocal & Equivalent Value Scientific Notation
1 cd/in² 144.000006 lm/(ft²·sr) 1.44 × 10²
5 cd/in² 720.000028 lm/(ft²·sr) 7.2 × 10²
10 cd/in² 1440.000056 lm/(ft²·sr) 1.44 × 10³
50 cd/in² 7200.000279 lm/(ft²·sr) 7.2 × 10³
100 cd/in² 14400.000557 lm/(ft²·sr) 1.44 × 10⁴
View Complete 15-Row Candela/square inch to Lumen/sq. foot/steradian Table

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 Lumen/sq. foot/steradian (lm/(ft²·sr)) and Candela/square inch (cd/in²):

Lumen/sq. foot/steradian References:

  • Commercial cinema movie theater projection screen brightness 4.6452 lm/(ft²·sr)
  • Standard indoor office computer desktop monitor peak brightness 27.8709 lm/(ft²·sr)
  • High-end smartphone HDR screen peak outdoor sunlight brightness 139.35 lm/(ft²·sr)
  • Clear blue daytime sky zenith ambient luminance 464.52 lm/(ft²·sr)

Candela/square inch References:

  • Commercial cinema movie theater projection screen brightness 0.032258 cd/in²
  • Standard indoor office computer desktop monitor peak brightness 0.193548 cd/in²
  • High-end smartphone HDR screen peak outdoor sunlight brightness 0.96774 cd/in²
  • Clear blue daytime sky zenith ambient luminance 3.2258 cd/in²

Tap any benchmark above to automatically calculate its exact equivalent in Candela/square inch.

ISQ Dimension: [L⁻² J] Coherent SI Unit: candela per square meter (cd/m²) Photometry, Radiometry, Optics & Acoustics

How to Convert Lumen/sq. foot/steradian to Candela/square inch

Converting Lumen/sq. foot/steradian (lm/(ft²·sr)) to Candela/square inch (cd/in²) is a core calculation in Luminance, which measures the photometric luminous intensity emitted or reflected per unit area in a given direction. 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 Lumen/sq. foot/steradian equals 0.00694444 Candela/square inch, while 1 cd/in² equals 144.000006 lm/(ft²·sr).

Direct Factor1 lm/(ft²·sr) = 0.00694444 cd/in²
Inverse Ratio1 cd/in² = 144.000006 lm/(ft²·sr)
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 (candela per square meter (cd/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 lm/(ft²·sr) = 10.76391 candela per square meter (cd/m²)
2. Target SI Bridge (ktarget):1 cd/in² = 1550.0031 candela per square meter (cd/m²)
Step-by-step substitution for Lumen/sq. foot/steradian → Candela/square inch:V(cd/in²) = V(lm/(ft²·sr)) × ( 10.76391 / 1550.0031 ) = V(lm/(ft²·sr)) × 0.00694444
Mathematical FormulaValue in Candela/square inch = Value in Lumen/sq. foot/steradian × 0.0069444442Direct computational formula applied for standard conversion.
Worked Example

For an engineering input of 8 lm/(ft²·sr), applying the conversion factor yields exactly 0.0555556 cd/in². At larger operational scale, 100 Lumen/sq. foot/steradian corresponds to 0.694444 cd/in².

Inverse check: 1 cd/in² = 144.000006 lm/(ft²·sr).

Understanding Lumen/sq. foot/steradian and Candela/square inch

Lumen/sq. foot/steradian

lm/(ft²·sr)
Imperial / US

A Lumen/sq. foot/steradian (lm/(ft²·sr)) is an imperial and US customary unit for luminance.

Applications & Practical Context

In practical luminance terms, a commercial cinema movie theater projection screen brightness equals 4.6452 lm/(ft²·sr), a standard indoor office computer desktop monitor peak brightness equals 27.8709 lm/(ft²·sr), a high-end smartphone HDR screen peak outdoor sunlight brightness equals 139.35 lm/(ft²·sr).

Physical Setup

A physical magnitude of 1 lm/(ft²·sr) corresponds to 10.76391 cd/m² in standard SI measurement.

Conversion to SI Unit: candela per square meter (cd/m²)
1 lm/(ft²·sr) = 10.76391 cd/m²

Candela/square inch

cd/in²
Imperial / US

A Candela/square inch (cd/in²) is an imperial and US customary unit for luminance.

Applications & Practical Context

In practical luminance terms, a commercial cinema movie theater projection screen brightness equals 0.032258 cd/in², a standard indoor office computer desktop monitor peak brightness equals 0.193548 cd/in², a high-end smartphone HDR screen peak outdoor sunlight brightness equals 0.96774 cd/in².

Physical Setup

A physical magnitude of 1 cd/in² corresponds to 1550.0031 cd/m² in standard SI measurement.

Conversion to SI Unit: candela per square meter (cd/m²)
1 cd/in² = 1550.0031 cd/m²

Domain Metrology & Engineering Applications

Governing Law & Equation

Surface Photometric Radiance (L_v = d²Φ_v / (dA·cosθ·dΩ))

Measurement Instrumentation

Rigorously quantified in laboratory and field settings using narrow-angle spot luminance meters, imaging colorimeters, and spectroradiometers.

Primary Industry Sectors

Applied across OLED/LCD display brightness calibration (nits), road tunnel entrance lighting, avionics cockpit HUD readability, and highway signage legibility under international metrology standard ISO 80000-7:2019, CIE 018:2019.

Physical Orders of Magnitude & Laboratory Reference Benchmarks

Physical Phenomenon / Engineering ReferenceReference ValueConverted to Candela/square inch
Commercial cinema movie theater projection screen brightness50 cd/m²0.347222 cd/in²
Standard indoor office computer desktop monitor peak brightness300 cd/m²2.083333 cd/in²
High-end smartphone HDR screen peak outdoor sunlight brightness1500 cd/m²10.416666 cd/in²
Clear blue daytime sky zenith ambient luminance5000 cd/m²34.722221 cd/in²
Institutional Metrology & Standard Authority:

Formulas, conversion coefficients, and base definitions on this page strictly adhere to the ISO 80000-7:2019, CIE 018:2019 and the BIPM SI Brochure (9th Edition). Governed by Surface Photometric Radiance (L_v = d²Φ_v / (dA·cosθ·dΩ)) under ISO 80000 dimensional vector [L⁻² J].

Multi-Variable Engineering Bridge Display Brightness & Surface Emission

Surface Luminance to Total Luminous Intensity Bridge (Candela • Candlepower • Hefnerkerze • Millicandela • Kilocandela)

Calculate total directional luminous intensity I_v = L_v × A from emissive displays and optical diffusers, bridging surface luminance [L⁻² J] and luminous intensity [J] via aperture area (A).

I_v = L_v × A
Vector: [cd/m²] × [m²] → [cd]
Live Calculated Bridge Equivalent:
1 lm/(ft²·sr) at 15.6" Laptop Display (0.067 m²) = 0.7212 cd
Equals 0.7356 cp • 0.7983 HK • 0.07515 carcel
SI Luminous Intensity
0.7212
cd
Candela
Historical English
0.7356
cp
Candlepower
German Standard
0.7983
HK
Hefnerkerze
French Standard
0.07515
carcel
Carcel Unit
Indicator LED
721.18
mcd
Millicandela
Lighthouse Beacon
0.0007212
kcd
Kilocandela
  1. 1. Normalize Input to SI Base Unit (cd/m²):
    L_v = 1 lm/(ft²·sr) × 10.76391 = 10.76391 cd/m²
  2. 2. Apply Engineering Parameter (A):
    Selected condition: 15.6" Laptop Display (0.067 m²) at A = 0.067 m²
  3. 3. Execute Governing Physical Law in SI Units:
    I_v = L_v × A = (10.76391 cd/m²) × (0.067 m²) = 0.721182 cd
  4. 4. Convert to Standard Engineering Units:
    • cd: 0.721182 × 1 = 0.7212 cd (Candela) • cp: 0.721182 × 1.02 = 0.7356 cp (Candlepower) • HK: 0.721182 × 1.107 = 0.7983 HK (Hefnerkerze) • carcel: 0.721182 × 0.1042 = 0.07515 carcel (Carcel Unit) • mcd: 0.721182 × 1000 = 721.18 mcd (Millicandela) • kcd: 0.721182 × 0.001 = 0.0007212 kcd (Kilocandela)
Explore Luminous Intensity Converter →
Engineering Substance / Operating Standard Parameter Value (m²) Reference State / Condition Typical Industrial & Engineering Application
6.1" Smartphone Screen (0.009 m²) 0.009 0.009 m² (90 cm²) OLED mobile display panel surface aperture
15.6" Laptop Display (0.067 m²) 0.067 0.067 m² (670 cm²) Commercial notebook IPS screen aperture
55" Ultra HD Television (0.834 m²) 0.834 0.834 m² (8,340 cm²) Living room 4K LED/OLED television surface
LED Replacement Bulb Frosted Lens (0.005 m²) 0.005 0.005 m² (50 cm²) Standard A19 household diffuser globe
Commercial Outdoor LED Billboard (18 m²) 18 18.0 m² (194 ft²) Highway electronic digital billboard face
Embed
Need this Lumen/sq. foot/steradian to Candela/square inch 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 0.0069444442 candelas/square inch (cd/in²) in 1 lumen/sq. foot/steradian (lm/(ft²·sr)). To calculate larger amounts manually, simply multiply your total number of lumens/sq. foot/steradian by the conversion multiplier of 0.0069444442.

The mathematical formula to convert lumens/sq. foot/steradian to candelas/square inch is: [value] * 0.0069444442 = candelas/square inch. 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 candelas/square inch back to lumens/sq. foot/steradian, you must divide your starting value by 0.0069444442. Our bidirectional tool automatically computes this inverse equation the moment you type into the candela/square inch input field.

1 Candela/square inch is larger than 1 Lumen/sq. foot/steradian. Specifically, 1 Lumen/sq. foot/steradian equals 0.0069444442 candelas/square inch, meaning 1 Candela/square inch is 144 times larger than 1 Lumen/sq. foot/steradian (a difference of 2.16 orders of magnitude). Expressing measurements in lumens/sq. foot/steradian requires a larger numerical value to represent the equivalent physical magnitude.

Under standard international measurement guidelines, 1 Lumen/sq. foot/steradian converts to 0.0069444442 candelas/square inch. Precise numerical conversion factors ensure consistency across laboratory, engineering, and field data.

Physically Coupled Optics & Acoustics Converters

Explore interconnected physical dimension converters within the Optics & Acoustics cluster (ISO 80000-7:2019 / ISO 80000-8:2020).

View Hub
Frequency Dimensional Hub & Tools
Sound Dimensional Hub & Tools
Luminous Intensity Dimensional Hub & Tools
Illumination Dimensional Hub & Tools
Digital Image Resolution Dimensional Hub & Tools