669 ppb to ppm

669 ppb = 0.669 ppm

ppbppm
654 ppb0.654
659 ppb0.659
664 ppb0.664
6690.669
674 ppb0.674
679 ppb0.679
684 ppb0.684

669 ppb = 0.669 ppm

Formula

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