What this calculator does
Radiation Pressure works out pressure an electromagnetic wave, like sunlight, exerts on an absorbing or reflecting surface. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Intensity (solar constant ≈ 1361) (W/m²) | A number, measured in W/m². Starts at 1361. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with intensity (solar constant ≈ 1361)
Every other input is held at the calculator’s starting values while intensity (solar constant ≈ 1361) varies. Select any row to load that scenario into the calculator.
| Intensity (solar constant ≈ 1361) (W/m²) | Radiation pressure (absorbing surface) | Radiation pressure (perfectly reflecting) | Radiation pressure (absorbing) |
|---|---|---|---|
| 681 | 2.2716e-6 Pa | 4.5431e-6 Pa | 2.2716e+0 µPa |
| 1,021 | 3.4057e-6 Pa | 6.8114e-6 Pa | 3.4057e+0 µPa |
| 1,361 | 4.5398e-6 Pa | 9.0796e-6 Pa | 4.5398e+0 µPa |
| 2,042 | 6.8114e-6 Pa | 1.3623e-5 Pa | 6.8114e+0 µPa |
| 2,722 | 9.0796e-6 Pa | 1.8159e-5 Pa | 9.0796e+0 µPa |
| 4,083 | 1.3619e-5 Pa | 2.7239e-5 Pa | 1.3619e+1 µPa |