Mixing oil weights

Here's a viscosity calculator for mixing any two oils.
Mixing viscosities | Widman International

The viscosity of pretty much any oil can be found on the manufacture's website. Some are easier to find than others, but they all have it. It will be given at 40 C and 100 C. That's the standard. To know the oil viscosity at other temps, put those two numbers in this calculator.
Graph your oils | Widman International