Oil Blending
Viscosity Calculator
Find the resulting viscosity when blending two oils, or calculate the exact ratio needed to reach a target viscosity. Based on the ASTM D341 Walther equation.
Important: Only blend oils of the same base type, type and formulation. Mixing incompatible oils can damage equipment and void warranties. Always consult your technical supplier before blending.
Calculator 1 — Blend Viscosity
Know the proportions → calculate the resulting viscosity
Kinematic viscosity of oil 1 at 40 °C
0%50% Oil 1100%
Calculated per ASTM D341 (Walther / VBN method). Enter both viscosities measured at the same temperature.
Calculator 2 — Blend Ratio for Target Viscosity
Know the desired viscosity → calculate how much of each oil to blend
The lighter or heavier of the two
Target viscosity must lie between the viscosities of the two oils. A viscosity outside that range cannot be achieved by blending.
ISO VG Quick Reference (40 °C)
Each ISO VG grade accepts ±10% of the nominal value at 40 °C (ISO 3448).
| Grade | Nominal (cSt) | Min (cSt) | Max (cSt) |
|---|---|---|---|
| ISO VG 22 | 22 | 19.8 | 24.2 |
| ISO VG 32 | 32 | 28.8 | 35.2 |
| ISO VG 46 | 46 | 41.4 | 50.6 |
| ISO VG 68 | 68 | 61.2 | 74.8 |
| ISO VG 100 | 100 | 90.0 | 110.0 |
| ISO VG 150 | 150 | 135.0 | 165.0 |
| ISO VG 220 | 220 | 198.0 | 242.0 |
| ISO VG 320 | 320 | 288.0 | 352.0 |
| ISO VG 460 | 460 | 414.0 | 506.0 |
| ISO VG 680 | 680 | 612.0 | 748.0 |
| ISO VG 1000 | 1000 | 900.0 | 1100.0 |
| ISO VG 1500 | 1500 | 1350.0 | 1650.0 |
Need technical advice?
Our engineering team can help you select the right lubricant for your application.