628 ppb to ppm

628 ppb = 0.628 ppm

ppbppm
613 ppb0.613
618 ppb0.618
623 ppb0.623
6280.628
633 ppb0.633
638 ppb0.638
643 ppb0.643

628 ppb = 0.628 ppm

Formula

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