The diagram below indicates the minimum and maximum viscosities in centistokes for equivalent ISO-VG grades at temperature 40oC.

ISO VG stands for "International Standards Organization Viscosity Grade" and is a number ranged from 2 to 1500.
Equivalent Viscosity of ISO-VG Grades at 40oC and SAE Crankcase Oil Grades
ISO-VG Grade | SAE Crankcase Oil Grade |
22 | 5W |
32 | 10W |
46 | 15W |
68 | 20W |
100 | 30 |
150 | 40 |
220 | 50 |
320 | 60 |
Equivalent Viscosity of ISO-VG Grades at 40oC and SAE Aircraft Oil Grades
ISO-VG Grade | SAE Aircraft Oil Grade |
100 | 65 |
150 | 80 |
220 | 100 |
320 | 120 |
Equivalent Viscosity of ISO-VG Grades at 40oC and SAE Gear Lube Grades
ISO-VG Grade | SAE Gear Lube Grade |
46 | 75W |
100 | 80W-90 |
220 | 90 |
460 | 85W-140 |
1500 | 250 |
Equivalent Viscosity of ISO-VG Grades at 40oC and AGMA Gear Lube Grades
ISO-VG Grade | AGMA Gear Lube Grade |
Regular | EP |
46 | 1 | |
68 | 2 | 2 EP |
100 | 3 | 3 EP |
150 | 4 | 4 EP |
220 | 5 | 5 EP |
320 | 6 | 6 EP |
460 | 7 | 7 EP |
680 | 8 | 8 EP |
ISO-VG Grades - Absolute Viscosity vs. Temperature, Reyns vs. Fahrenheit

ISO-VG Grades - Absolute Viscosity vs. Temperature, centiPoise vs. Celsius

- tC = 5/9(tF - 32)
- tF = 9/5 tC + 32
- 1 reyns (lb s/in2) = 6896.55 (Pa s)
- 1 cSt (centiStoke) = 1 centiPoise / SG
- SG = specific gravity of oil