630 ppb to ppm

630 ppb = 0.63 ppm

ppbppm
615 ppb0.615
620 ppb0.62
625 ppb0.625
6300.63
635 ppb0.635
640 ppb0.64
645 ppb0.645

630 ppb = 0.63 ppm

Formula

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