Convert Proton Mass to Neutron Mass
Convert proton mass to neutron mass instantly. 1 proton mass = 0.9986235234 neutron mass — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Neutron Mass to Proton Mass converter for the reverse conversion.
Units explained
Proton Mass
The proton rest mass is about 1.6726E-27 kg.
The mass of the proton, the positively charged nucleon.
Nuclear and particle physics, and chemistry.
Quantified after Rutherford identified the proton around 1917-1920.
Neutron Mass
The neutron rest mass is about 1.6749E-27 kg, slightly more than the proton.
The mass of the neutron, the neutral nucleon.
Nuclear physics and reactor science.
Determined after James Chadwick discovered the neutron in 1932.
Proton Mass to Neutron Mass conversion formula
Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.
The relationship between proton mass and neutron mass:
To convert proton mass to neutron mass, multiply the value in proton mass by 0.9986235234. To reverse, multiply neutron mass by 1.0013783739.
How to use this converter
Type a value into the calculator. The result in neutron mass updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Neutron Mass to Proton Mass converter for the reverse direction.
Step-by-step: convert proton mass to neutron mass
- Write down the value in proton mass (mp).
- Multiply that value by the factor 0.9986235234.
- The product is the equivalent value in neutron mass (mn).
- To reverse, multiply the neutron mass value by 1.0013783739.
Worked examples
Example 1 — Convert 1 mp to mn:
1 × 0.9986235234 = 0.9986235234 mn
Example 2 — Convert 100 mp to mn:
100 × 0.9986235234 = 99.8623523415 mn
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 proton mass) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 mp × 0.9986235234 = 1.9972470468 mn
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 proton mass can be re-expressed in neutron mass for direct comparison with another instrument's calibration data sheet.
800 mp × 0.9986235234 = 798.8988187317 mn
Proton Mass to Neutron Mass conversion table
Standard reference values for converting proton mass to neutron mass:
| Proton Mass [mp] | Neutron Mass [mn] |
|---|---|
| 0.01 | 0.0099862352 |
| 0.1 | 0.0998623523 |
| 1 | 0.9986235234 |
| 2 | 1.9972470468 |
| 3 | 2.9958705702 |
| 4 | 3.9944940937 |
| 5 | 4.9931176171 |
| 10 | 9.9862352341 |
| 20 | 19.9724704683 |
| 30 | 29.9587057024 |
| 40 | 39.9449409366 |
| 50 | 49.9311761707 |
| 100 | 99.8623523415 |
| 500 | 499.3117617073 |
| 1000 | 998.6235234147 |
Frequently asked questions
How many neutron mass is 1 proton mass?
How do I convert proton mass to neutron mass?
How do I convert neutron mass back to proton mass?
How many neutron mass is 100 proton mass?
Popular weight unit conversions
Convert Proton Mass to other weight units
Show all Proton Mass conversions
Metric / SI (18 units)
Avoirdupois (15 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (8 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 mp = 0.9986235234 mn) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.