ONE FORMULA, ONE ANSWER
Weber Number Calculator
Calculate the ratio of inertia to interfacial-tension effects for a stated characteristic length and relative speed. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Weber number We
Enter values and select Calculate.
We = ρV²L / σ
Assumptions
Required: density, characteristic length and relative speed consistent with the chosen reference phase and phenomenon, with constant interfacial tension. Excluded: inferring universal droplet-breakup, spray or bubble-shape thresholds from We alone.
Displayed values are floating-point approximations. Design safety factors and unprovided error contributions are not calculated.
Formula references and credits
- MIT: Surface-tension dimensionless groups
- MIT 2.25 · Surface-tension dimensionless groups, original notes
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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