2.5 ppb to ppm

2.5 ppb = 0.003 ppm

ppbppm
1 ppb0.001
1.5 ppb0.002
2 ppb0.002
2.50.003
3 ppb0.003
3.5 ppb0.004
4 ppb0.004

2.5 ppb = 0.003 ppm

Formula

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