Phots to Nox Converter
Enter the illumination in phots below to convert it to nox.
Convert Phots to Nox
Enter a value in phots (ph) to convert to nox (nx).
Phot to Nox Conversion Table
Table showing various phot measurements converted to nox. Click any preset value or arrow to load it into the converter.
How to Convert Phots to Nox
To convert phots to nox, multiply the illumination by the following conversion ratio: 10,000,000 nox/phot.
Since one phot is equal to 10,000,000 nox, you can use this simple formula to convert:
The illumination in nox is equal to the illumination in phots multiplied by 10,000,000.
For example, here's how to convert 5 phots to nox using the formula above.
How Many Nox Are in a Phot?
There are 10,000,000 nox in a phot, which is why we use this value in the formula above.
Our phot to nox calculator automatically converts your illumination measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Phots and nox are both units used to measure illumination. Keep reading to learn more about each unit.
What Is a Phot?
A phot is a unit of illumination equal to 10,000 lux (lx), the base unit for illumination. CGS illuminance unit equal to 10,000 lux. [1]
The phot is classified as a metric and SI-compatible unit of illumination. Phots can be abbreviated as ph; for example, 1 phot can be written as 1 ph.
When working with phots (ph) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, phots (ph) are widely used across large-scale industrial, bulk, and macro-level illumination specifications within SI metric workflows, engineering documentation, and technical data sheets.
What Is a Nox?
A nox is a unit of illumination equal to 1/1,000 of a lux (0.001 lx). Dark-adapted illuminance unit equal to 1 millilux (0.001 lx). [2]
The nox is classified as a metric and SI-compatible unit of illumination. Nox can be abbreviated as nx; for example, 1 nox can be written as 1 nx.
When working with nox (nx) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, nox (nx) are widely used across fine-tolerance laboratory, analytical, and micro-scale illumination measurements within SI metric workflows, engineering documentation, and technical data sheets.
When converting illumination between phots (ph) and nox (nx), keep full floating-point precision (1 ph = 10,000,000 nx; 1 nx = 0.0000001 ph) during intermediate calculations and round only the final nox figure to match your instrument tolerance.
More Phot & Nox Conversions
Need to calculate in the opposite direction? Use our nox to phots calculator to switch your starting unit immediately. You can also explore related tools such as converting nox to phots, converting lux to kilolux, or converting kilolux to lux.
Convert from Phots
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Illumination Metrology Standard — Phots (ph) to Nox (nx)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Phot (lm/cm²) (ph) & Nox (nx)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (ph to nx)