720.5 ppb to ppm

720.5 ppb = 0.721 ppm

ppbppm
705.5 ppb0.706
710.5 ppb0.711
715.5 ppb0.716
720.50.721
725.5 ppb0.726
730.5 ppb0.731
735.5 ppb0.736

720.5 ppb = 0.721 ppm

Formula

1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm