What this calculator does
Aerodynamic drag force works out drag force on an object moving through a fluid, from its shape and speed. 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
FormulaFd = ½ρv²ACd
The inputs explained
| Field | What to enter |
|---|---|
| Fluid density (air ≈ 1.225) (kg/m³) | A number, measured in kg/m³. Starts at 1.225. |
| Speed (m/s) | A number, measured in m/s. Starts at 25. |
| Reference (frontal) area (m²) | A number, measured in m². Starts at 1.5. |
| Drag coefficient | A number. Starts at 0.3. |
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 fluid density (air ≈ 1.225)
Every other input is held at the calculator’s starting values while fluid density (air ≈ 1.225) varies. Select any row to load that scenario into the calculator.
How the answer changes with fluid density (air ≈ 1.225)