UHVMate is a tool for quickly analyzing several aspects of ultra-high vacuum (UHV) systems. You might still need the back of an envelope, but throw those data tables away.

Conductance:
How fast can a pipe or aperture transport gas under UHV molecular flow conditions? UHVMate includes the parameters for standard ConFlat-style parts, and allows arbitrary pipe diameter and length calculations. Pre- and post-bake conditions are treated by calculating conductance for both nitrogen and hydrogen gases.

Outgassing:
Build a model of your UHV system from a library of over 90 standard ConFlat-style parts, including some Kimball Physics chambers. Add quantities of outgassing metals, glasses, or elastomers. Then, select a pumping speed and conductance, and the ultimate base pressure is calculated. The only grain of salt to take is that UHVMate assumes a uniform effective pumping speed, outgassing, and therefore pressure.

Saturated vapor pressure:
UHVMate incorporates known coefficients for many elements, allowing for the calculation of vapor pressure as a function of temperature. Also shown are the materials' melting points, and several other temperature dependent properties inferred from ideal gas laws: mean free path, number density, mean speed, and molecular impingement rates.