Planck units are a system of natural units based on fundamental physical constants (Planck's constant, speed of light, gravitational constant) that represent the smallest meaningful scales in physics where current physical laws break down. These 15 units include Planck time (time for light to travel one Planck length), Planck length (100 quintillionth of a proton), Planck mass (21.76 micrograms), Planck temperature (maximum theoretical temperature), Planck charge, Planck energy, Planck force, Planck power, Planck density, Planck pressure, Planck acceleration, Planck angular frequency, Planck impedance, Planck voltage, and Planck area. Each unit has a specific symbol combining a base letter with a subscript 'P' for Planck, representing the scale at which quantum effects and gravity become inseparable.
Deep Dive
Prerequisite Knowledge
- No data available.
Where to go next
- No data available.
Deep Dive
Planck Units - All the Planck Units Explained- KLT Fan SongAdded:
[music] >> We are the Planck units and there are 13 of us. We'll tell you our names and symbols without making a fuss.
I am the Planck time and I am the amount of time light takes to travel one Planck length. One Planck length is 100 quintillionth of the length of a proton.
I tell you this with all of my strength.
My symbol is an italic T followed by an upper case subscript letter P. The T stands for tempus, which is the Latin word for time, and the P is short for Planck. I tell you this as I rhyme. I am the Planck length. I am 100 quintillionth the length of a proton, just like the Planck time said. My symbol is a lower case italic letter L followed by a subscript capital letter P. You already know that the P stands for Planck, and the L stands for length.
I am the Planck mass. I tell you in this class. I am roughly 21.76 micrograms in weight. If we add weighs roughly one Planck mass, and my symbol is an italic lower case M followed by again a subscript letter P, that is capital. Yes, the P stands for Planck, you should know, and the M stands for mass.
>> [music] >> I am a Planck volume, and I am defined as a cube of the Planck length in this room.
My symbol is a capital italic letter V followed by again a subscript capital letter P. That's enough about me.
I am the Planck temperature and I should have been in the units OF TEMPERATURE SONG. WHY WASN'T I?
WHATEVER.
I am the Planck temperature and I am the theoretical maximum temperature in the universe. I mark the point where current physical laws, including gravity and quantum mechanics, break down. I wish I crazy that I was able to take a bow.
>> [music] >> I am the Planck charge and I am very large. I represent the scale at which quantum effects and gravity are expected to dominate.
My symbol is a lowercase italic letter Q followed by a subscript capital letter P, as you can plainly see. I am the Planck energy. My symbol is capital E followed by a subscript lowercase letter P. I am considered the largest observable form of particle energy.
I hope you enjoyed this course. I am a Planck force. I am the largest possible unit of force allowed in nature. My symbol is an uppercase F followed by a subscript uppercase letter P. I hope you enjoyed learning all about me. This is for sure. I am a Planck power. My symbol is a capital P followed by a subscript capital letter P. I am a theoretically large upper limit of power and I am the point where gravity and quantum effects merge.
>> [music] >> I am the Planck density. I am extremely dense, as you can plainly see. I am equal to 10 to the 23rd power of the sun's mass being compressed into an atomic nucleus. I tell you this for the best. My symbol is the Greek letter rho followed by a subscript uppercase letter P, as you can see. I'm known as the Planck pressure. Everything I'm telling you is very sure. I'm equal to 10 to the 108th power kilograms resting on every single square centimeter. That's an unfathomably large amount of pressure. I hope you enjoyed this song every single word.
>> [music] >> My symbol is a lowercase P followed by a subscript uppercase letter P.
I am the Planck acceleration.
You should learn about me in this station. I'm the acceleration required for an object to go from being completely still to moving as fast as the speed of light in just one Planck time. That's right.
My symbol is a lowercase A followed by a subscript uppercase P.
>> [music] >> I am the Planck angular frequency. I am the last Planck >> Hey.
Huh? You forgot about us. Should I go ahead and include you guys? Yes. Okay, I promise I'll give you your parts when I finish mine. Anyway, I am the Planck angular frequency. My symbol is the Greek omega followed by a subscript uppercase P. I represent the highest possible physical frequency of an oscillation or rotation before classical descriptions of space and time becoming invalid. That is my description. I hope you do not change it. I'm the Planck impedance and I'm the characteristic resistance of a vacuum tube electromagnetic wave. In this business, my symbol is an uppercase Z followed by a subscript uppercase P. I am the Planck voltage. I'm the unit of electric potential representing an extreme voltage difference across a Planck length. My symbol is an uppercase V followed by a subscript uppercase P. I tell you this with all my strength.
I am the Planck area. I'm physically defined as the square of the Planck length. I tell this to you. My symbol is an uppercase A followed by a subscript uppercase letter P. I tell you this, hooray. Thank you for learning all about the Planck units. Now, let's sing the chorus three times. We are the Planck units and there are 15 of us. We told you our names and symbols without making a fuss. We are the Planck units and there are 15 of us. We told you our names and symbols without making a fuss.
We are the Planck units and there are 15 of us. We told you our names and symbols without making a fuss.
>> [music]
Related Videos
Is dark matter real? - Why can't we find it? - physicist explains | Don Lincoln and Lex Fridman
LexClips
1K views•2026-05-30
Saptarshi Basu - Spectacular Voyage of Droplets: A Multiscale Journey to Extreme Flow Conditions
DAlembert-SU-CNRS
152 views•2026-06-02
A 6.0 Just Hit Hawaii — And It Came From The Wrong Place
TerraWatchHQ
115 views•2026-06-03
The Split-Second Mistake That Made Bouncing Bettys So Deadly
NoMansLandChannel
253 views•2026-06-02
Nobody Expected This Lava Reaction 🤯 #faits #facts
TendzDora
28K views•2026-05-30
The Difference In Charged And Neutral Particles
heavybrainspace
959 views•2026-05-29
The Silent Memory of Glass
UnchartedScienceworld
146 views•2026-05-30
A380 vs Every Vehicles Crash Test Challenge | Which One Win?
BeamLap
163 views•2026-05-29











