How this calculator works
Young-Laplace pressure equals surface tension times the sum of principal curvatures. The spherical mode assumes two equal radii and one interface. Tube modes combine spherical-meniscus geometry with hydrostatic balance, giving signed rise for wetting angles below 90 degrees and depression above 90 degrees. Enter surface tension and density difference at the actual temperature and composition. Absolute inside/outside pressure modes perform the signed pressure balance separately.
Formula
Delta p = gamma(1/R1 + 1/R2); sphere: Delta p = 2 gamma/R. Capillary height h = 2 gamma cos(theta)/(rho g a).
Worked example
With gamma = 0.072 N/m and R = 0.001 m, the spherical pressure jump is 144 Pa. With rho = 1000 kg/m3, g = 9.80665 m/s2, tube radius 0.001 m and angle 0 degrees, rise is about 0.014684 m.
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Frequently asked questions
What about a soap bubble?
A thin soap bubble has two interfaces, giving approximately 4 gamma/R rather than the single-interface spherical result here.
Can capillary height be negative?
Yes. A contact angle greater than 90 degrees gives depression under this sign convention.
Does this solve an arbitrary meniscus shape?
No. It uses spherical curvature or the circular-tube approximation, not a numerical surface-shape solution.