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Wind Profile Visualization
This calculator estimates how wind speed changes with height above the ground using the logarithmic wind profile — a widely used approximation in boundary-layer meteorology. The atmosphere's surface layer, roughly the lowest 100 m, is strongly influenced by friction with the ground. Obstacles like trees, buildings, and terrain features slow the wind near the surface, and the wind speed increases logarithmically with height.
The formula assumes neutral atmospheric stability (no strong thermal convection or temperature inversion) and homogeneous terrain surrounding the measurement site. These are reasonable assumptions for most wind resource assessment and weather station siting applications, but the model becomes less accurate in strongly convective or stable atmospheric conditions, over complex terrain, or at heights above approximately 100–200 m where the surface layer gives way to the outer boundary layer.
Enter the height of your anemometer or weather station above ground level, the measured wind speed, and the height at which you would like to estimate the wind speed. Then select a roughness class from the dropdown that best describes the terrain surrounding your measurement site, or enter a custom roughness length value directly. The estimated wind speed at your target height updates automatically, and the visualization on the right redraws to show the wind profile curve, mast, and terrain.
Tip: If your weather station is mounted at 2 m on a rooftop and you want to know what the wind speed would be at the standard meteorological height of 10 m in open terrain, this calculator provides a first approximation — but keep in mind that rooftop measurements are affected by building-induced turbulence that the log profile does not capture.
The roughness length z0 characterizes the aerodynamic roughness of the terrain surrounding your measurement site. Select the description that best matches your location. The energy index column shows the relative wind energy available compared to an ideal open-water surface (class 0 = 100%).
| Class | z0 (m) | Energy Index | Landscape Description |
|---|---|---|---|
| 0 | 0.0002 | 100% | Water surface |
| 0.5 | 0.0024 | 73% | Completely open terrain with a smooth surface, such as concrete runways in airports, mowed grass |
| 1 | 0.03 | 52% | Open agricultural area without fences and hedgerows and very scattered buildings; only softly rounded hills |
| 1.5 | 0.055 | 45% | Agricultural land with some houses and 8 m tall sheltering hedgerows within a distance of approximately 1250 m |
| 2 | 0.1 | 39% | Agricultural land with some houses and 8 m tall sheltering hedgerows within a distance of approximately 500 m |
| 2.5 | 0.2 | 31% | Agricultural land with many houses, shrubs and plants, or 8 m tall sheltering hedgerows within a distance of approximately 250 m |
| 3 | 0.4 | 24% | Villages, small towns, agricultural land with many or tall sheltering hedgerows, forests and very rough and uneven terrain |
| 3.5 | 0.8 | 18% | Larger cities with tall buildings |
| 4 | 1.6 | 13% | Very large cities with tall buildings and skyscrapers |
The logarithmic wind profile is an industry-standard approximation used in wind energy site assessment (per IEC 61400-12-1) and meteorological station siting. However, users should be aware of the following assumptions built into this model:
Neutral stability: The formula assumes a neutrally stratified atmosphere. During strong daytime heating (unstable conditions), actual wind shear may be less than predicted. During nighttime inversions (stable conditions), wind shear may be greater than predicted.
Homogeneous terrain: The roughness length should be representative of the terrain for several kilometres upwind of the measurement site. If the terrain changes significantly (e.g., a transition from water to land), the wind profile will be more complex than this model predicts.
Height range: This model is most reliable within the atmospheric surface layer, typically the lowest 100–200 m above ground. For wind turbine hub heights above this range, a power-law profile or more advanced boundary-layer models may be more appropriate.
Not suitable for rooftops or complex obstacles: If the anemometer is mounted on a building rooftop, chimney, or near large obstacles, the local flow field is dominated by building aerodynamics rather than the surface roughness, and the log profile should not be used without corrections.