Online calculators

There are several little online calculators on this site.

• Linear interpolator
  
• Quadratic interpolator
• Distance from longitude and latitude
• Cubic equations
• Converting between music notation, frequency, and barks
• Converting between phon and sone (loudness metrics)
• LaTeX commands to/from Unicode characters
• Fraction approximation for a decimal
• Predicting a child’s adult height
• How far is a degree at your longitude and latitude
• Pythagorean triangle approximation
• Half-life calculator
• Wavelength to RGB