Physical Constants Reference Calculator
Look up common physical constants by number, scale them by a quantity, and convert mass to energy with E equals mc squared.
Compare Your Options And Get Clear Answers
Look up common physical constants by number, scale them by a quantity, and convert mass to energy with E equals mc squared.
Physical Constants Reference Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Choose
Enter the number of the constant from 1 to 8.
Scale
Multiply by any quantity you need.
Convert Mass
Enter a mass to get its energy in joules.
Check Units
Always carry the unit with the value.
Constants List
Constant numbers used by this tool.
| Number | Constant | Value | Unit |
|---|---|---|---|
| 1 | Speed of light | 299792458 | m/s |
| 2 | Standard gravity | 9.80665 | m/s2 |
| 3 | Planck constant | 6.626e-34 | J s |
| 4 | Boltzmann constant | 1.381e-23 | J/K |
| Also | 5 Avogadro | 6 Gas constant | 7 Charge, 8 G |
Physical Constants Reference Calculator FAQ
Answers to common questions about this calculator.
Fixed quantities of nature that are used throughout physics and chemistry.
Since 2019 the speed of light, Planck constant, Boltzmann constant, Avogadro constant and elementary charge are exact by definition.
No. It is measured and has the largest uncertainty of these constants.
It links mass and energy using the speed of light squared.