PPM to Ratio Calculator

About this calculator

Parts per million is a dimensionless concentration unit that this calculator converts three ways: to percent by dividing by 10,000 (since 1% = 10,000 ppm), to a 1:N ratio where N = 1,000,000 / ppm, and to milligrams per liter, which for dilute aqueous solutions is numerically equal to ppm because water's density is close to 1 kg/L.

Environmental scientists and water treatment operators work in ppm and mg/L interchangeably when reporting contaminant or chlorine concentrations, agricultural technicians use ppm to mix fertilizer and pesticide solutions to label-specified strengths, and chemists convert between these units constantly since lab instruments, safety data sheets and regulatory limits each tend to favor a different one.